OBS local oauth

This is an adaptation from OBS oauth Cloudflare Worker to be run on any linux machine.

This will hopefully allow more linux users to run their own oauth proxy, and allow them to use the service integrations in OBS.

Limitations

• No restream implementation. As I do not use Restream I have no use to implement it's support, any PR to fix that is welcome.
• This is not tested on Windows, MacOS or any *BSD. I don't have any of them, if you have a bug on one of these platform you may report it, but I do not guarantee that I will fix it.

License

This project is under the GPL-2.0
The code in src/platforms/oauth.rs is under the license of OBS oauth cf. It's only there as a reference and will be deleted in the next commit