Ingame menu, camera pan & auto-alignment controls, profiles

[3phedra]

A bit belated, but here's the PR.

This adds an imgui ingame menu for all available configs; changes are immediate.

Beyond that, and per request, I've added a profile mechanism for the exploration and combat settings. These get stored in the usual toml file.

The code previously clamped min zoom, which I've changed to be more adaptive. E.g. there is now a guard preventing a min value to be higher than the max value.

I've added a camera pan control, which toggles intercepting button presses / function calls that would detach the camera from an actor. To complement this feature, another addition is the optional camera auto-alignment behind an actor. Technically meant to be used with the WASD mod.
Still needs testing with controllers, for which for now I left some debug logging in.

There's a debug toggle in the menu, which enables a new debug tab. I've used this to find the player entity heading and left it in for future use.

Note that the menu currently only works in the DX11 version of the game.