Password validator custom error messages

[bcail]

We would like to make it easier to customize the error messages raised by ​password validators.

Instead of having to override whole methods, could we put the error messages on the class as attributes, so we would only have to override that attribute for each class?

See ​the forum thread for discussion.

Note: ticket 34116 is a related ticket that was closed as wontfix, but it was asking for being able to pass the custom error messages through the settings, which is not what this ticket is suggesting.

[Claude Paroz]

Makes sense to me.

[Dmitriy Chukhin]

I reviewed the ​/pull request and confirmed that the change is working; do we need to update anything in the documentation based on the change?

[Dmitriy Chukhin]

The ​/pull request (including additions to documentation) look good to me, so I approved it.

[Sarah Boyce <42296566+sarahboyce@…>]

In 80c3697:

Refs #35782 -- Documented the get_help_text methods in password validators.

[Sarah Boyce <42296566+sarahboyce@…>]

In ec7d6903:

Fixed #35782 -- Allowed overriding password validation error messages.