Interface Support for Signals

[Extrys]

Is your feature request related to a problem? Please describe.
Declaring Concrete signal types
make posible just subscribing to that concrete type
so i can not normally subscribe to interfaces of fired signals

Describe the solution you'd like
What i want is to declare the signals in a way that it's interfaces do it too
and when i fire the concrete signal, interfaces declarations do it too

Describe alternatives you've considered
just working normally coupling the concrete types to the subscriptors

[Extrys]

#91 Resolves this issue

[Mathijs-Bakker]

Continuous Integration workflow is running smoothly. It will now run the tests from the test suite and create Unity builds for all the supported targets.

You can now do your PR again.

Cheers!