Bring back accessible "required" form validation message

[patcon]

^{ℹ️ Figma (root) | Sitemap This initial comment is collaborative and open to modification by all.}

Related: https://github.com/GCTC-NTGC/gc-digital-talent/pull/3630 https://github.com/GCTC-NTGC/gc-digital-talent/issues/3588

Removed {fieldLabel} from defaulted field error message (causing issues with react-intl and failing tests)

Description

First off, deep apologies for not seeing the problem with adding a token to the default required message https://github.com/GCTC-NTGC/gc-digital-talent/pull/3536. I think the green CI tests made my brain turn off :/ Thanks to Eric for reverting 🙏

Anyhow, since the purpose was a11y, prob worth fixing. The intention of the var in the string was so that the default message would include reference to the field, and screen-readers would be giving more context when they interrupt with feedback.

Proposed steps:

• [ ] add a v2 string for errorMessages.requiredV2 https://github.com/GCTC-NTGC/gc-digital-talent/blob/12545c4ab5e7809437e2cd3f91cc7f0a5f0f5c99/frontend/common/src/messages/errorMessages.ts#L4-L14
• [ ] use it within https://github.com/GCTC-NTGC/gc-digital-talent/blob/12545c4ab5e7809437e2cd3f91cc7f0a5f0f5c99/frontend/common/src/components/form/Select/SelectFieldV2.tsx#L98
• [ ] re-enable hook test 26338963e254ab8
• [ ] re-enable component tests 8668fa2f4465e474c77a007dfd63bbb6e4f3fc66
• [ ] create new issue to deprecate v1 required string (non-accessible)
  • most of it's uses will disappear once we migrate from Select and MultiSelect to SelectField and MultiSelectField (#3384 and #3128), but it might also be used in some other places like radio or checkbox fields, in which case it'll need to be accommodate manually (by passing the field name).

Acceptance Criteria

• [ ] all SelectField and MultiSelectField components have a accessible default "required" validation message, with a mention of field label
• [ ] all existing uses of errorMessages.required still work
• [ ] SelectField and MultiSelectField stories work

[patcon]

Alternative approach of simple wrapping useForm in a custom useForm (useFormCustom?) that adds the default messages: https://github.com/react-hook-form/react-hook-form/issues/458#issuecomment-1265907115

[esizer]

Closing in favour of #5416 since it has suggestions about the messages that should be presented.