Committed Changes for DNN-5909 - GetFoldersByPermission Performance Improvement

Changes to the GetFoldersbyPermission procedure to improve performance.  Change was removing "Users" and "UserRoles" from the last query in the procedure.  These tables are un-used, not returned, and not filtering any data.  Removing these reduce the CPU cost greatly.  Full details on DNN JIRA ticket 5909!
Because it's such a big performance win, I'd think it would be best to remove the joins and preserve the semantic equivalence with a predicate, and then (in a separate work item) explore whether changing the query is the right thing to do.  I'm not very familiar with how the procedure is actually used in the framework.