Allow fixing unicode files with non-ASCII characters on Windows

[BayerGL]

Description

Cannot run autoimport on a UTF-8 file with cyrillic characters on Windows.

Steps to reproduce

> autoimport <any_file_with_non_ascii>.py

Current behavior

Traceback (most recent call last):
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Users\user\Projects\MyProject\.venv\Scripts\autoimport.exe\__main__.py", line 7, in <module>
  File "C:\Users\user\Projects\MyProject\.venv\lib\site-packages\click\core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
  File "C:\Users\user\Projects\MyProject\.venv\lib\site-packages\click\core.py", line 1078, in main
    rv = self.invoke(ctx)
  File "C:\Users\user\Projects\MyProject\.venv\lib\site-packages\click\core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "C:\Users\user\Projects\MyProject\.venv\lib\site-packages\click\core.py", line 783, in invoke
    return __callback(*args, **kwargs)
  File "C:\Users\user\Projects\MyProject\.venv\lib\site-packages\autoimport\entrypoints\cli.py", line 94, in cli
    fixed_code = services.fix_files(flattened_files, config)
  File "C:\Users\user\Projects\MyProject\.venv\lib\site-packages\autoimport\services.py", line 28, in fix_files
    source = file_wrapper.read()
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\encodings\cp1251.py", line 23, in decode
    return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x98 in position 29668: character maps to <undefined>

Desired behavior

Just works and fixes the file.

Environment

Windows 11
Python 3.9
autoimport==1.3.3

I made a workaround for myself by adding encoding='utf-8' at

autoimport/src/autoimport/entrypoints/cli.py

Line 24 in 485d430

files.append(click.File("r+").convert(py_file, None, None))

            files.append(click.File("r+", encoding='utf-8').convert(py_file, None, None))

and at

autoimport/src/autoimport/entrypoints/cli.py

Line 52 in 485d430

return [click.File("r+").convert(value, param, ctx)]

            return click.File("r+", encoding='utf-8').convert(value, param, ctx)

But it would be better to have a special encoding parameter at the command line arguments and/or in the pyproject.toml configuration file.

[lyz-code]

Hi @BayerGL thanks for taking the time to open the issue. I feel your workaround may work for many people so if you want to make a pull request I'll be glad to review it. If you would like to go a step further and implement the command line parameter that would be awesome too.