Ensure join correctness for enums of different types

[angelamayxie]

fixes dolthub/dolt#10311

branched from #3381

Enums of different types join based on their string value, not their underlying int value. Ensures join correctness for enums of different types by doing the following:

• use type-aware conversion with enum origin types to properly convert enums to their string values
• disable Lookup joins for enums of different types. Lookup joins should not work here because enums are indexed based on their int values.
• disable Merge joins for enums of different types. Merge joins should not work here because enums are sorted based on their int values.