Replaced broken UserFormsGridFieldFilterHeader with a SearchFilter and the default GridFieldFilterHeader

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Description

This PR fixes the long standing issue #919 where UserFormsGridFieldFilterHeader would never show up by replacing it with a standard GridFieldFilterHeader and a new SearchFilter. UserFormsGridFieldFilterHeader has not been removed to avoid a breaking change but it is deprecated and no longer used by default. Note: Like UserFormsGridFieldFilterHeader this just uses a case insensitive match on the value not a partial match.

Manual testing steps

1. Create a user form
2. Create a field with the "Show in summary search" checkbox set
3. Fill out and submit the form a couple times to seed some submissions
4. On the submissions tab expand the "Search options" and search by the form field created in 2

Issues

• UserFormsGridFieldFilterHeader never shows up in the CMS #919

Pull request checklist

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• CI is green