Insert fails for blobs >= 2^16 bytes

Depending on the exact method used, we can get two different stack traces and error messages.

## Method 1: `LOAD_FILE`

repro steps:

```
dd if=/dev/zero of=blobfile bs=65536 count=1
dolt sql -q "create table files (pk int primary key, file blob);"
dolt sql -q "insert into files values (1, load_file('blobfile'));"
```

error: `interface conversion: interface {} is []uint8, not string`

Stack trace:
```
/Users/nick/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.23.3.darwin-arm64/src/runtime/iface.go:275 (0x100c34627)
panicdottypeE: panic(&TypeAssertionError{iface, have, want, ""})
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/rowexec/insert.go:327 (0x10238d61b)
com/dolthub/go-mysql-server/sql/rowexec.convertDataAndWarn: row[columnIdx] = row[columnIdx].(string)[:maxLength] // truncate string
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/rowexec/insert.go:118 (0x10238ca2b)
com/dolthub/go-mysql-server/sql/rowexec.(*insertIter).Next: row = convertDataAndWarn(ctx, i.schema, row, idx, cErr)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/plan/table_editor.go:121 (0x102102e9f)
com/dolthub/go-mysql-server/sql/plan.CheckpointingTableEditorIter.Next: row, err := c.inner.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/rowexec/dml_iters.go:606 (0x102389aeb)
com/dolthub/go-mysql-server/sql/rowexec.(*accumulatorIter).Next: row, err := a.iter.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/rowexec/transaction_iters.go:86 (0x1023bd627)
com/dolthub/go-mysql-server/sql/rowexec.(*TransactionCommittingIter).Next: return t.childIter.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/plan/process.go:306 (0x1020dc50f)
com/dolthub/go-mysql-server/sql/plan.(*TrackedRowIter).Next: row, err := i.iter.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/server/handler.go:489 (0x1027267c7)
com/dolthub/go-mysql-server/server.resultForOkIter: row, err := iter.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/server/handler.go:447 (0x1027261c3)
com/dolthub/go-mysql-server/server.(*Handler).doQuery: r, err = resultForOkIter(sqlCtx, rowIter)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/server/handler.go:759 (0x102728dd7)
com/dolthub/go-mysql-server/server.(*Handler).errorWrappedDoQuery: remainder, err := h.doQuery(ctx, c, query, parsed, nil, mode, h.executeQuery, bindings, callback, qFlags)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/server/handler.go:310 (0x1027254d3)
com/dolthub/go-mysql-server/server.(*Handler).ComQuery: _, err := h.errorWrappedDoQuery(ctx, c, query, nil, MultiStmtModeOff, nil, callback, &sql.QueryFlags{})
/Users/nick/go/pkg/mod/github.com/dolthub/vitess@v0.0.0-20241209181212-588631aba4be/go/mysql/conn.go:1569 (0x10118af73)
com/dolthub/vitess/go/mysql.(*Conn).execQuery: err = handler.ComQuery(ctx, c, query, resultsCB)
/Users/nick/go/pkg/mod/github.com/dolthub/vitess@v0.0.0-20241209181212-588631aba4be/go/mysql/conn.go:1002 (0x101186763)
com/dolthub/vitess/go/mysql.(*Conn).handleNextCommand: for query, err = c.execQuery(ctx, query, handler, multiStatements); err == nil && query != ""; {
/Users/nick/go/pkg/mod/github.com/dolthub/vitess@v0.0.0-20241209181212-588631aba4be/go/mysql/server.go:524 (0x1011a16db)
com/dolthub/vitess/go/mysql.(*Listener).handle: err := c.handleNextCommand(ctx, l.handler)
/Users/nick/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.23.3.darwin-arm64/src/runtime/asm_arm64.s:1223 (0x100ca6103)
goexit: MOVD R0, R0 // NOP
```

## Method 2: inline file in query

repro.py:

```py
import pymysql

db = pymysql.connect(unix_socket="/tmp/mysql.sock", user="root", database="repro")
cur = db.cursor()

blob = b'x' * 65536
cur.execute("insert into files values (1, _binary %s)", (blob,))
cur.execute("commit")
```

error: `interface conversion: interface {} is string, not []uint8`

stack trace:

```
/Users/nick/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.23.3.darwin-arm64/src/runtime/iface.go:275 (0x100c34627)
panicdottypeE: panic(&TypeAssertionError{iface, have, want, ""})
/Users/nick/Documents/dolt/go/store/prolly/tree/prolly_fields.go:263 (0x101ae4b0f)
com/dolthub/dolt/go/store/prolly/tree.PutField: h, err := SerializeBytesToAddr(ctx, ns, bytes.NewReader(v.([]byte)), len(v.([]byte)))
/Users/nick/Documents/dolt/go/libraries/doltcore/sqle/writer/prolly_index_writer.go:148 (0x102760313)
com/dolthub/dolt/go/libraries/doltcore/sqle/writer.prollyIndexWriter.Insert: if err := tree.PutField(ctx, m.mut.NodeStore(), m.valBld, to, sqlRow[from]); err != nil {
/Users/nick/Documents/dolt/go/libraries/doltcore/sqle/writer/prolly_table_writer.go:160 (0x102766dff)
com/dolthub/dolt/go/libraries/doltcore/sqle/writer.(*prollyTableWriter).Insert: if err = w.primary.Insert(ctx, sqlRow); err != nil {
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/rowexec/insert.go:164 (0x10238c40f)
com/dolthub/go-mysql-server/sql/rowexec.(*insertIter).Next: if err := i.inserter.Insert(ctx, row); err != nil {
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/plan/table_editor.go:121 (0x102102e9f)
com/dolthub/go-mysql-server/sql/plan.CheckpointingTableEditorIter.Next: row, err := c.inner.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/rowexec/dml_iters.go:606 (0x102389aeb)
com/dolthub/go-mysql-server/sql/rowexec.(*accumulatorIter).Next: row, err := a.iter.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/rowexec/transaction_iters.go:86 (0x1023bd627)
com/dolthub/go-mysql-server/sql/rowexec.(*TransactionCommittingIter).Next: return t.childIter.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/sql/plan/process.go:306 (0x1020dc50f)
com/dolthub/go-mysql-server/sql/plan.(*TrackedRowIter).Next: row, err := i.iter.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/server/handler.go:489 (0x1027267c7)
com/dolthub/go-mysql-server/server.resultForOkIter: row, err := iter.Next(ctx)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/server/handler.go:447 (0x1027261c3)
com/dolthub/go-mysql-server/server.(*Handler).doQuery: r, err = resultForOkIter(sqlCtx, rowIter)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/server/handler.go:759 (0x102728dd7)
com/dolthub/go-mysql-server/server.(*Handler).errorWrappedDoQuery: remainder, err := h.doQuery(ctx, c, query, parsed, nil, mode, h.executeQuery, bindings, callback, qFlags)
/Users/nick/go/pkg/mod/github.com/dolthub/go-mysql-server@v0.18.2-0.20241209182739-d644619dc9ed/server/handler.go:310 (0x1027254d3)
com/dolthub/go-mysql-server/server.(*Handler).ComQuery: _, err := h.errorWrappedDoQuery(ctx, c, query, nil, MultiStmtModeOff, nil, callback, &sql.QueryFlags{})
/Users/nick/go/pkg/mod/github.com/dolthub/vitess@v0.0.0-20241209181212-588631aba4be/go/mysql/conn.go:1569 (0x10118af73)
com/dolthub/vitess/go/mysql.(*Conn).execQuery: err = handler.ComQuery(ctx, c, query, resultsCB)
/Users/nick/go/pkg/mod/github.com/dolthub/vitess@v0.0.0-20241209181212-588631aba4be/go/mysql/conn.go:1002 (0x101186763)
com/dolthub/vitess/go/mysql.(*Conn).handleNextCommand: for query, err = c.execQuery(ctx, query, handler, multiStatements); err == nil && query != ""; {
/Users/nick/go/pkg/mod/github.com/dolthub/vitess@v0.0.0-20241209181212-588631aba4be/go/mysql/server.go:524 (0x1011a16db)
com/dolthub/vitess/go/mysql.(*Listener).handle: err := c.handleNextCommand(ctx, l.handler)
/Users/nick/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.23.3.darwin-arm64/src/runtime/asm_arm64.s:1223 (0x100ca6103)
goexit: MOVD R0, R0 // NOP
```

Note that the errors, while similar, are different: `interface conversion: interface {} is []uint8, not string` vs `interface conversion: interface {} is string, not []uint8`