Support non-strict SQL modes

Dolt currently behaves similarly to MySQL with `STRICT_TRANS_TABLES` mode enabled, which means (among other things) that trying to insert a value outside the accepted range for a column, like a `VARCHAR` with more than the allowed characters, returns an error and aborts the transaction. MySQL 8.0 runs in `STRICT_TRANS_TABLES` by default, but older versions of MySQL ran in a mode that would silently truncate such values to fit the column and log a warning. You can still get this behavior in MySQL by tuning the SQL mode, but Dolt doesn't respect these settings.

See https://dev.mysql.com/doc/refman/8.0/en/sql-mode.html#sqlmode_strict_trans_tables for more information.

Related: https://github.com/dolthub/dolt/issues/2162

Start by comparing Dolt's current SQL-mode behavior with the linked MySQL SQL-mode documentation and related issue #2162. Trace where SQL mode is configured and where out-of-range inserts are validated; done means the relevant non-strict setting is honored with truncation and warnings rather than an aborted transaction, with coverage for the example.

Written by the indexing model from the issue text.