Drop support for silencing errors about DDL in transactions

[greg0ire]

I hesitated between this and removing the transaction helper entirely, but I think this solution will result in less support for us. Let me know if you think I should remove the transaction helper.

[SenseException]

If the helper class is kept in 4.0, it can only be removed in a 5.0 release, right? It doesn't seem to be widely in use now.

[greg0ire]

I think the choice is between removing it in 4.0, or keeping it forever, for DX reasons.

[derrabus]

The method naming is odd now. The names end with IfInTransaction which suggests that I can also safely call the method without an active transaction. But that's not the case anymore.

[greg0ire]

Ok, I'll switch to just commit and rollback then.