Filtering and paging done at DB level

• Status field is no longer Transient, so we can filter on it (requires DB update)
• Filtering and Paging can then be moved to the database, which makes it much more efficient (so no longer loading all requests when the requests controller is called)
• Sorting is done by default on the ID field in DESC
• Tabs on course page were unreadable
• Could not move to next page on Requests list