pass strings by const reference and use find_last_not_of

[soyersoyer]

const reference opportunities were advised by cppcheck to skip copy construction

[github-actions]

Build for testing:
MiniDexed_2024-12-30-37ce0ee
Use at your own risk.

[probonopd]

If I understand it right:

• It improves the efficiency of string handling by using const std::string & instead of std::string as function parameters. This avoids unnecessary string copies and reduces memory allocation.
• It simplifies the code in CPerformanceConfig::SetNewPerformanceName by using the find_last_not_of method to remove trailing spaces from the input string. This replaces the original loop that iterated over the string to find the last non-space character.
• The changes are consistent across multiple files (minidexed.cpp, minidexed.h, performanceconfig.cpp, and performanceconfig.h), ensuring that the improvements are applied uniformly throughout the codebase.

Thanks @soyersoyer. Were you able to test it thoroughly so it's low risk to merge?

[soyersoyer]

Yes.

[diyelectromusic]

Remember I'm not a C++ expert, but from what I think I know of references, I can't see any issues with this.