sql: support for Bun ORM

[Bun](https://github.com/uptrace/bun) is a more frequently updated ORM recommended in place of pg-go should someone need an actively maintained ORM. Looks like most of the tests pass and the unsupported ones could be skipped for now.

Running the Bun tests against CRDB resulted in:
```
❯ ./test.sh
+ trap 'docker-compose down -v' EXIT
+ docker-compose down -v
+ docker-compose up -d
[+] Running 2/2
⠿ Network dbtest_default Created 0.0s
⠿ Container dbtest-postgres-1 Started 0.2s
+ sleep 10
+ CGO_ENABLED=0
+ TZ=
+ go test
--- FAIL: TestListenerReceive (0.22s)
listener_test.go:28:
Error Trace: listener_test.go:28
Error: Received unexpected error:
ERROR: at or near "notify": syntax error (SQLSTATE=42601)
Test: TestListenerReceive
--- FAIL: TestListenerChannel (0.01s)
listener_test.go:66:
Error Trace: listener_test.go:66
Error: Received unexpected error:
ERROR: at or near "notify": syntax error (SQLSTATE=42601)
Test: TestListenerChannel
--- FAIL: TestORM (0.44s)
--- FAIL: TestORM/pg (0.04s)
orm_test.go:586:
Error Trace: orm_test.go:586
orm_test.go:41
db_test.go:94
Error: Received unexpected error:
ERROR: at or near "restart": syntax error (SQLSTATE=42601)
Test: TestORM/pg
--- FAIL: TestORM/pgx (0.40s)
orm_test.go:586:
Error Trace: orm_test.go:586
orm_test.go:41
db_test.go:94
Error: Received unexpected error:
ERROR: at or near "restart": syntax error (SQLSTATE 42601)
Test: TestORM/pgx
--- FAIL: TestPostgresCopyFromCopyTo (0.00s)
pg_test.go:557:
Error Trace: pg_test.go:557
Error: Received unexpected error:
ERROR: temporary tables are only supported experimentally (SQLSTATE=XCEXF)
Test: TestPostgresCopyFromCopyTo
--- FAIL: TestPostgresHStore (0.00s)
pg_test.go:665:
Error Trace: pg_test.go:665
Error: Received unexpected error:
ERROR: unimplemented: extension "hstore" is not yet supported (SQLSTATE=0A000)
Test: TestPostgresHStore
--- FAIL: TestPostgresHStoreQuote (0.01s)
pg_test.go:713:
Error Trace: pg_test.go:713
Error: Received unexpected error:
ERROR: unimplemented: extension "hstore" is not yet supported (SQLSTATE=0A000)
Test: TestPostgresHStoreQuote
FAIL
exit status 1
FAIL github.com/uptrace/bun/internal/dbtest 6.199s
+ docker-compose down -v
[+] Running 2/1
⠿ Container dbtest-postgres-1 Removed 1.3s
⠿ Network dbtest_default Removed
```

Bun should work without these features, but they are listed below for tracking:

- [ ] https://github.com/cockroachdb/cockroach/issues/38931
- [ ] https://github.com/cockroachdb/cockroach/issues/41522
- [ ] https://github.com/cockroachdb/cockroach/issues/41284

Jira issue: CRDB-22392

Epic CRDB-25316