Add a few missing settings

[danielsreichenbach]

This PR adds a few missing settings.

• packages now have storage settings. This resolves an issue where without any settings package uploads would simply fail
• LFS storage now has complete Minio settings, since without these LFS would fail in a non HTTP scenario
• OAuth enablement no longer uses deprecated flag
• generic storage settings can now have checksum algorithm
• actions can now be fully configured
• admin con now be fully configured

Hope this helps, we're using these changes in production already and these fixes resolve a few issues preventing Forgejo from properly working for us.

[bodsch]

Thank you for your pull request!