refactor: ♻️ rename check to check_value in CustomCheck

[martonvago]

Description

I thought there were so many "check"s around, and this method actually checks the value of a field, not the descriptor/properties.

Needs a quick review.

Checklist

• Formatted Markdown
• Ran just run-all

[lwjohnst86]

This works fine with me. Though, what do you think of something like condition instead of check_value?

[signekb]

I actually don't mind it being "check" here, bc it's the actual check that the custom check will perform, right? :)

[martonvago]

This works fine with me. Though, what do you think of something like condition instead of check_value?

I like it!

[martonvago]

Hmm, I guess I'll hold off on this until we decide what to do with required checks.