Small fixes around path detections

[dime10]

Includes:

• Fix cleanup of wheel artifacts

  • now includes an include directory
  • bin directory was moved a while ago one level up

• Fix misleading package_root variable

  • now it points to the actual package root, not the utils directory
  • since we're using os.join, we should use it for all path separators

• Remove obsolete get_bin_dir function

  • only used in a test, not even to get the bin dir but the lib dir
  • add catalyst dialects build dir to the default lib paths

• Add cli path fallback for rare wheel setups

  The catalyst binary used to be shipped right within the package, under
  catalyst/bin. This is no longer the case, since pip will install the
  binary into the dedicated binary location for Python packages.
  However, we may still encounter a configuration where the binary is
  located in a bin folder next to the catalyst package folder,
  specifically:

  • after make wheel we'll have frontend/bin next to frontend/catalyst,
    although we rarely directly test this configuration since it's more
    of a setup step to packaging the wheel.
  • when trying to emulate the above configuration for a quick
    frontend-only editable install, e.g. by extracting wheel contents
    over a checked-out catalyst repo.

[github-actions]

Hello. You may have forgotten to update the changelog!
Please edit doc/releases/changelog-dev.md on your branch with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
• Your name (or GitHub username) in the contributors section.