We should no longer rely on MYISAM for the sequence table since this
engine might not always be available. After this change the storage
engine used by the sequence table can be MYISAM or INNODB since the
sequences are allocated using a new connection without being
affected by any other transactions that might be in progress.
To allow users to fall back on the original functionality of using
MYISAM tables for the incrementer, we add a `useNewConnection` flag to
indicate whether or not to use a new connection for the incrementer.
This flag defaults to true.
Issue: SPR-15107
5c7aee7d38