Add error-field to force invalid form

[qroll]

Changes

• A field that when present, forces the form to be invalid
• Exposes an error rule to customise the message
• [delete] branch

Changelog entry

• Add support for error-field

[weili-govtech]

can we update it according to the changes in FEE?

• tighten validation type
• add children

[qroll]

the change to let custom rules extend IUnitNumberFieldValidationRule actually ended up causing more issues

• on Typescript 4, I get this error
• in yup-helper.ts, the rules couldn't be recognised due to the intersection of e.g. IUnitNumberFieldValidationRule | IYupValidationRule stripping away non-common properties

in the end I excluded the error field from TFieldValidation because it doesn't contribute to the typical rule evaluation anyway

[weili-govtech]

I think this is not needed, instead the rest of the custom rules in schemas should extend from IYupValidation (looks like we really missed this out)