* Added logic to check for executables in a local `binaries` directory.
* Enhanced Windows support by checking for `.exe` extensions.
* Removed unnecessary `binaries/` entry from `.gitignore`.
* Updated the `services` directory assignment to ensure it is always treated as a list, improving consistency in configuration handling. Allows to provide multiple different service folders.
* Introduced `SubtitleCodecChoice` to allow selection of subtitle codecs with support for enum names, values, and common aliases.
* Updated `--sub-format` option in `dl.py` to utilize the new `SubtitleCodecChoice`.
