Auth: Move access control API to SignedInUser interface (#73144)

* move access control api to SignedInUser interface

* remove unused code

* add logic for reading perms from a specific org

* move the specific org logic to org_user.go

* add a comment

---------

Co-authored-by: IevaVasiljeva <ieva.vasiljeva@grafana.com>

pkg/services/accesscontrol/api/api.go

@@ -114,7 +114,8 @@ func (api *AccessControlAPI) searchUserPermissions(c *contextmodel.ReqContext) r
 		return response.JSON(http.StatusBadRequest, "provide one of 'action' or 'actionPrefix'")
 	}
 
-	permissions, err := api.Service.SearchUserPermissions(c.Req.Context(), c.OrgID, searchOptions)
+	permissions, err := api.Service.SearchUserPermissions(c.Req.Context(),
+		c.SignedInUser.GetOrgID(), searchOptions)
 	if err != nil {
 		response.Error(http.StatusInternalServerError, "could not search user permissions", err)
 	}