XYZ-37: Advanced Permissions Phase 1 Backend. (#8159)

* XYZ-13: Update Permission and Role structs to new design.

* XYZ-10: Role store.

* XYZ-9/XYZ-44: Roles API endpoints and WebSocket message.

* XYZ-8: Switch server permissions checks to store backed roles.

* XYZ-58: Proper validation of roles where required.

* XYZ-11/XYZ-55: Migration to store backed roles from policy config.

* XYZ-37: Update unit tests to work with database roles.

* XYZ-56: Remove the "guest" role.

* Changes to SetDefaultRolesFromConfig.

* Short-circuit the store if nothing has changed.

* Address first round of review comments.

* Address second round of review comments.

web/web_test.go

@@ -52,6 +52,8 @@ func Setup() *app.App {
 	URL = fmt.Sprintf("http://localhost:%v", a.Srv.ListenAddr.Port)
 	ApiClient = model.NewClient(URL)
 
+	a.DoAdvancedPermissionsMigration()
+
 	a.Srv.Store.MarkSystemRanUnitTests()
 
 	a.UpdateConfig(func(cfg *model.Config) {