[clang] [clang-tools-extra] [clang] skip explicit obj param in code complete (PR #146258)

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MythreyaK wrote:

Thank you for patiently giving me pointers and links! Definitely came in handy!

I just noticed that I didn't follow a pattern with the test naming. 
* Something along the lines of "ignore/skip `self` parameter in deducing this" is more user-friendly
* "ignore/skip explicit object parameter" is probably consistent with the C++ feature 

Open to suggestions for more descriptive names! (I'm bad with names :D)

https://github.com/llvm/llvm-project/pull/146258