Include validation check for single table auto_assign_transformers

[lajohn4747]

resolves #1509 CU-85ztjjzrw

Include better messsaging for auto_assign_transformers by checking metadata and data before going through assigning the transformers.

[sdv-team]

Task linked: CU-85ztjjzrw SDV - Better data validation message for auto_assign_transformers #1509

[lajohn4747]

Does this work for multi table?

Yes it does, I added a test to multitable to confirm it as well. Multitable synthesizer handles auto_assign_transformer at the table level which happens to call the single table auto_assign_transformer function