[NEW FEATURE] Change the directory where the configuration file is located

[Vixb1122]

New feature

I would like to be able to specify the directory where the configuration files are located so that they can be managed. This would also make it easier to uninstall the software.

Additional context

mpv: D:\Macast
app config: %LOCALAPPDATA%\xfangfang\Macast → D:\Macast\config
mpv config: %APPDATA%\mpv → D:\Macast\mpv

➜  Macast tree -L 2
.
├── config
│   ├── macast.log
│   ├── macast_setting.json
│   ├── protocol
│   └── renderer
├── macast.exe
└── mpv
    └── watch_later

5 directories, 3 files