Add filter to product metrics

[Maffooch]

Add a filter to the product metrics page

• Give a meaningful name to your PR, as it may end up being used in the release notes.
• Your code is flake8 compliant.
• Your code is python 3.6 compliant (specific python >3.6 syntax is currently not accepted).
• If this is a new feature and not a bug fix, you've included the proper documentation in the ReadTheDocs documentation folder. https://github.com/DefectDojo/Documentation/tree/master/docs or provide feature documentation in the PR.
• Model changes must include the necessary migrations in the dojo/db_migrations folder.
• Add applicable tests to the unit tests.
• Add the proper label to categorize your PR.

[mtesauro]

Approved