content views - ui - initial adding of filters and filter rules

This PR contains some initial code to support content view definition filters and filter rules in the UI (e.g. CRUD actions).  There is more work that will be coming for this; however, needed to get this PR created now, as it can be used for the work that is also occurring in parallel to support the publish/refresh with filters.

Refer to commits for all details.

Note: this PR does not include tests.  Tests will be added in a separate PR.  Also, this PR is going to a branch, not master.