Unification of 'open-folder' function, should fix 'xdg-open' path error

[BigBoyBarney]

Should fix #726 as long as xdg-open is in $PATH, which can be assumed for every distro. I tested it for GTK, Qt and CLI on Fedora 39.

[!CAUTION] As my other PR (#722), this requires python 3.10. Do not merge before #722 or without updating python dep.

Changes

Code

• Unified all 'open folder' functions in utils.py. Can take an error_callback param so error reporting can still be done uniquely for every UI.
• Fixed OSError not being raised when the folder was in the library, but was changed after scanning. I.e:
  1. Start trackma
  2. 'Show X' gets scanned and found
  3. Rename folder of 'show X'
  4. Open folder
  5. Error is raised correctly

[BigBoyBarney]

Thanks for the changes.

Which part of this PR requires Python 3.10? I'm not seeing it …

match sys.platform:
            case 'darwin':
                command = ["open", os.path.dirname(filename)]
            case 'win32':
                command = ["explorer", os.path.dirname(filename)]
            case _:
                command = ["xdg-open", os.path.dirname(filename)]

Match was introduced in Python 3.10