Field valid and invalid custom classes

[suspiciousRaccoon]

Adds 2 new parameters to the field renderer to allow overriding the default valid and invalid classes

Fixes #738

[dyve]

Thank you for the pull request!

Docs: https://getbootstrap.com/docs/5.0/forms/validation/

Looks like Bootstrap 5 defaults to pseudo classes. Let's check the standards before committing to an alternative.

[coveralls]

Pull Request Test Coverage Report for Build 12422610075

Details

• 16 of 16 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.02%) to 97.886%

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Totals
Change from base Build 12348252146:	0.02%
Covered Lines:	1421
Relevant Lines:	1442

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💛 - Coveralls

[TohidN]

Looks like Bootstrap 5 defaults to pseudo classes. Let's check the standards before committing to an alternative.

while Bootstrap standard is to use .is-invalid and .is-valid classes, this pull provides a roundabout solution for disabling validation for bound forms, as mentioned in #738