Support smaller decimal types through SQL interface

[AdamGS]

Part of #17489.

Due to a bug in arrow-rs, the new smaller decimal values couldn't have been used through the SQL interface. Now that arrow 56.2.0 is released (and soon to be updated here), support in datafusion-sql should be implemented + slt tests to verify the behavior of various aggregations which are supported now after #17501.

[AdamGS]

take