Replace config system with Pyside's QSettings

[twizmwazin]

Description

Currently we have our own config system implemented in angrmanagement.config. Instead of doing this ourselves, it would be a good idea to instead let QT handle this for us.

Alternatives

No response

Additional context

No response

[ltfish]

QSettings does not use toml and has some weird limitations (because it decides to use Windows Registry on Windows). I think using our own configuration system with a pure text-based backend will allow easier configuration backup and manual modification.

[twizmwazin]

From glancing over the API docs it seems that custom formats are supported. Assuming that is true it should be possible to migrate to QSettings with a toml backend that preserves compatibility with existing configs.