sql: increase the sqllogic test coverage

[maddyblue]

The following bugs need to be fixed before the sqllogic select tests can be enabled:

• support tables without a primary key? sql: support tables without a primary key? #2081
• comparison of float and int sql: comparison of float and int #3266
• integer division returns float, sqllogic test expects int sql: integer division returns float, sqllogic test expects int #3271
• add failing test for aliased subquery sql: implement EXISTS expressions #3291
• hide rowid column from select and inserts sql: hide rowid column from select and inserts #3293
• support JOIN sql: support JOIN #2970
• convert NULL to false sql: convert NULL to false #3544

[knz]

Closing as this is superseded by #7733 and #7734.