Fix name when copying filenames/directories containing "-Copy"

[RRosio]

This adds a condition to keep the original file/directory name when copying to a new directory.

• Issue where file containing "-Copy" into a new directory was being stripped (reported in bug in filebrowser: file-rename on copy/paste jupyterlab/jupyterlab#12236)
  • Also addresses related issue which happens when you copy a file "test" and another file "test-Copy" (which was previously stripped to just "test") and this resulted in mismatched file contents (reported in bug in filebrowser: Copy/paste of 2 files leads to content swap jupyterlab/jupyterlab#12237)

[RRosio]

It looks like Jupyter Server Tests / build (ubuntu-latest, 3.11) (pull_request) is failing due to pypa/hatch#2193

[krassowski]

@RRosio it should now work after restart :)

[Zsailer]

@RRosio thanks for fixing this!

Since we've got the same logic 4 times, do you mind making this a function and calling the function 4 times? That way, we can document and maintain the logic in a single place.

Also, let's add some unit tests to catch this case so we don't accidentally break this again in the future?