Webform Validation migration support from D7 to D9

There are two different issues for this - ✨ Webform_validation migration support from D7 to d9, 8.x-1.x supported. Closed: duplicate is the other one. Both have patches from the original author. I've closed the other one, all work should be done on this one.

The attached patch is rerolled on 2.0.x.

It also addresses feedback in comment 8 except for accounting for "negate" configuration. I'm only seeing that property on a few validation types and not on the "equals" one.

Also tested on a few clients and adjusted the schema to map correctly. And cleaned up a few PHP warnings.

Still needs an issue summary created.