Updates CSP to use new content_filtering option.
Splits out content filtering tests to their own class.
Updated tests where needed to adapt to changes.
Added and updated tests to cover.
Also updated API auth to a narrower focus of existing session instead of also existing user auth.
This is mainly for tests, to ensure they're following the session
process we'd see for activity in the UI.
- Added mulit-level depth parsing.
- Updating usage of HTML doc in page content to be efficient.
- Removed now redundant PageContentTest cases.
- Made some include system fixes based upon testing.
