* Added ReadingList age rating from all series and started on some unit tests for the new flows.
* Wrote more unit tests for Reading Lists
* Added ability to restrict user accounts to a given age rating via admin edit user modal and invite user. This commit contains all basic code, but no query modifications.
* When updating a reading list's title via UI, explicitly check if there is an existing RL with the same title.
* Refactored Reading List calculation to work properly in the flows it's invoked from.
* Cleaned up an unused method
* Promoted Collections no longer show tags where a Series exists within them that is above the user's age rating.
* Collection search now respects age restrictions
* Series Detail page now checks if the user has explicit access (as a user might bypass with direct url access)
* Hooked up age restriction for dashboard activity streams.
* Refactored some methods from Series Controller and Library Controller to a new Search Controller to keep things organized
* Updated Search to respect age restrictions
* Refactored all the Age Restriction queries to extensions
* Related Series no longer show up if they are out of the age restriction
* Fixed a bad mapping for the update age restriction api
* Fixed a UI state change after updating age restriction
* Fixed unit test
* Added a migration for reading lists
* Code cleanup
