Enable checking of repository settings, and add a specific tool for toggling secret scanning settings only.

Advanced Security is a pre-requisite for using this on private repos (and or Secret Protection SKU when it launches next week), so we will need to handle those quirks.

I had to make some manual http calls, because the go wrapper does not wrap this feature.

TODO before merge:

• decide on cleanest way to handle the public/private repo stuff where there is a pre-requisite to enabling secret protection
• we could just have a catch-all configuration setting endpoint, with the massive number of possible settings?
• I can make all fields optional, but the annoying thing is that you can't have push protection on, without secret protection. The API is not conducive to wrapping neatly in a tool, but I must find a way.
• can we also enable Code Scanning default setup?
• add tests