slapgrid.promise: Improve promise check speed
Use cache to save some promise instance information.
First run of slapgrid fill each promise cached (when there is no cache). The next run will check some usefull info like if promise is test less or promise is anomaly less directly from cache without need to import the module.
Cache is updated if promise file or module change, or if the promise periodicity expire (when the promise it update cache).