Check Licenses at Starttime

[Old-Shatterhand]

Is your feature request related to a problem? Please describe.
It would be nice to check licenses at the start of the program to see if they are valid.

Describe the solution you'd like
Just a quick check: Maybe calling the help function of the solver is enough.

Describe alternatives you've considered
So far, one has to run the whole program from scratch when figuring out that the license was invalid.

Additional context
None