GLASM is getting good enough that we can move it out of advanced
graphics settings. This removes the setting `use_assembly_shaders`,
opting for a enum class `shader_backend`. This comes with the benefits
that it is extensible for additional shader backends besides GLSL and
GLASM, and this will work better with a QComboBox.
Qt removes the related assembly shader setting from the Advanced
Graphics section and places it as a new QComboBox in the API Settings
group. This will replace the Vulkan device selector when OpenGL is
selected.
Additionally, mark all of the custom anisotropic filtering settings as
"WILL BREAK THINGS", as that is the case with a select few games.
Some titles crash if the FPS limit is disabled when launching. This change ensures that titles launch with the limit in-place to avoid issues.
In order to simplify the change, the UI toggle was removed as it will always be overridden at launch to be disabled.
The setting can still be toggled during gameplay with the hotkey, and indicated by the fps label in the status bar.
