[FR] Don't use regular expressions in user facing errors

### On which framework/platform would you like to see this feature implemented?

Angular

### Which UI component is this feature-request for?

Authenticator

### Please describe your feature-request in detail.

When a user is changing their password and it doesn't meet the password requirements, I see an error like this

I barely understand this as a developer, and to a user it is complete gibberish and not helpful at all.

### Please describe a solution you'd like.

It would be better if it showed what those password requirements actually were, or even if it just said something generic like "Password does not meet complexity requirements" or something it would be more helpful than that.

Please remove the use of regular expressions in all user facing error messages.

### We love contributors! Is this something you'd be interested in working on?

- [ ] 👋 I may be able to implement this feature request.
- [ ] ⚠️ This feature might incur a breaking change.

Start with the Angular Authenticator password-change flow and locate where the current password-requirement error is presented to users. Review the other user-facing errors in the Authenticator, then confirm that password failures and the identified errors communicate requirements without exposing regular-expression text.

Written by the indexing model from the issue text.