Renamed NrtErrorHandling C API

[bjauny]

Please check if the PR fulfills these requirements

• [x] The commit message follows our guidelines
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Documentation has been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...) Renamed all functions of NrtErrorHandling.h to comply with naming rules.

Is there an open issue that this resolves? Solves #547 .

What is the current behavior? (You can also link to an open issue here)

What is the new behavior (if this is a feature change)?

Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?) No, just a rename of functions.

Other information:

[RubyNova]

Looks to be in the right direction, nice start. :)

[RubyNova]

Hey there just as a reminder can you please make sure the PR matches our submission template? thanks.

[bjauny]

Hi there, finally caught'em all!

I pushed separated commits for the APIs I changed but I can happily squash them if you feel like it.

[RubyNova]

Hey, sorry this has taken so long, its in our backlog. We will review it soon.