API for getting fully-qualified name in Cpp target

[OmerMajNition]

Cpp runtime has support for fully qualified name but is not available to reaction bodies. This PR adds support for fqn() in reactions.

[lhstrh]

Can you please run ./gradlew spotlessApply to fix the formatting test failure?

[cmnrd]

Looks good! While at it, I think it would be nice to add name() as well.

The test currently only checks if fqn() is available. It would be better to also assert the expected values.

[OmerMajNition]

• ./gradlew spotlessApply Done
• Added name() support as well and validation in test file

[OmerMajNition]

Quick comment:

reactor-cpp/lib/reactor.cc line # 50

[[maybe_unused]] bool result = inputs_.insert(port).second;

should become

[[maybe_unused]] bool result = outputs_.insert(port).second;