feat: Add an option to get receive the batches in a script and be able to execute them.

[IvanDimitrovQC]

The function iter_executes_batches mimics executes, but instead of executing the SQL script internally it produces an iterator over each batch and a callable to execute that batch.

Useful if you have long SQL files with several queries inside them and would like to do some more granular analysis (for example runtime) on each one rather than the whole file.

EDIT:
I also adjust test_non_isolation_mode.test_semi_persistent_set by changing the ints as it fails in a funny way:

 '12' is contained here:
    INFO     pytsql:tsql.py:212 SQL PRINT: 56