We now validate the linkifier urls and patterns together, and add
the following additional checks:
1. All groups in the pattern must be used in the URL format string.
2. All groups in the URL format string must be declared in the pattern.
Linkifier pattern is now validated inside the `clean` method.
`filter_pattern_validator` is moved from `clean_fields` to `clean`
method as a safe check. As a result of this, a Puppeteer test case
is updated.
NOTE: The changes here are IN ADDITION to the existing validations.
Fixes#16482.
Co-authored-by: akshatdalton <akshat.dak@students.iiit.ac.in>
Rohitt Vashishtha