[Add-Feature] Add custom DXVK_HUD option

[quasd]

I basically have no idea what I am doing (dotnet?), if there is anything you would like to be changed let me know.

The current options for DXVK_HUD were not enough so I implemented custom switch for it.

Only visible when set to custom:

Result in game:

Tested on: arch build with customized: https://aur.archlinux.org/packages/xivlauncher-git