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!
From my initial investigation, there will always be an administrator role permission, so, there's not a case where there would _only_ be a user permission which would cause the folder to be excluded from the results when joining.  So I don't think there's a practical difference after removing the joins, and I don't think it's necessary to add a `FP.RoleID IS NOT NULL` clause to the `WHERE`