Graceful informing when more than one simulator is initialized in one the thread

[mathfac]

🚀 Feature

Inform: Only 1 habitat simulator is expected per process. Check if a previous instance of the simulator was closed properly. when more than one simulator is initialized in one thread.

Motivation

Now we have hard to interpret messages and a crash when more than one simulator are in the same thread: GL::Context: Another context currently active GL::Context::current(): no current context Usually that informs that previous instance of simulator wasn't closed properly.