Clear SessionStoredSim on project delete (and not only)

Have a simulation configured, finished with success, then select it ( SessionStoredSimulator should be not empty in memory)

delete the current project (in which the SessionStoredSimulator was defined)

in a different or new project go on the Simulator page

WRONG: we see the state of the previous SessionStoredSimulator loaded on the middle column

INSTEAD: we should clean SessionStoredSimulator from the current session when a project is deleted (or more generic when it is unselected)