* Fixed nullability warnings in `Utility.cs`
* Fixed a number of nullability issues and warnings
* More nullable fixes
* Fixed the overwrite issue
* Fixed additional nullability issues
* Removed additional nullability issues
* More nullability fixes and added some xmldoc
* Added more xmldocs and removed an unused argument
* Removed more warnings
Added auth requirement on all endpoints.
Added SignIn-, Access- and Refresh-Tokens based on JWT.
Upgraded stored password to be based on PBKDF2.
Added default password assignment.
Updated logic to support auth-header and re-sign-in for tray-icon and web-ui.
Re-implemented everything using ASP.NET.
Changed some requests to use JSON instead of FORM data.
Some work towards deleting the FIXMEGlobal instance.
Auth is missing, XSRF does not work correctly.
