Remove unecessary launch parameters and focus on environment variables

[h0m3]

For a program like protonlaunch or wine, launch parameters may become confusing so it may be better to deprecate and in the future remove most confusing and unecessary launch parameters and keep only launch environment variables.

[h0m3]

Added documentation to PL_QUIET and PL_DEBUG. Also added commented deprecation messages for --steam-path, --proton-version, --quiet and debug on commit 50f51c8