Due to dependencies on initializing some data in app_init it was not possible to cleanly set up the fonts.
This adds a game-side function for loading the entire palettes before starting with the texture data and another one for loading game-side texture data.
This now allows fully setting up the palettes before starting with the textures and to fully set up the textures before reading the .def files.
All this is needed because to properly initialize, the fonts need to be able to access the fully initialized texture state, including replacements and hires substitutions from the .def files.
Mainly this means that it's no longer necessary to reorder the palette to get working translated glyphs, so the FFontChar1 class and the TranslatedPic member and its invasive handling could all be cleaned out.
All font operations now take place on true color data, with the sole execption of FSpecialFont's 'notranslate' handling.
The base palette can be set via .def files so that the engine has no access to it until the entire game state is set up.
This means that font translations and PNG palette remap tables cannot be built when the owning objects are created.
For PNGs this has the added advantage that they only get done when really required and not unconditionally - most of the time the remap table isn't even needed here.
Thid fixes the slider graphics in the option menus.
# Conflicts:
# source/core/gamecontrol.cpp
# Conflicts:
# source/core/gamecontrol.cpp
This pulls in a lot of Doom specific font setup, this can be sorted out later as it won't get into the way.
# Conflicts:
# source/CMakeLists.txt
# Conflicts:
# source/glbackend/hw_draw2d.cpp
# Conflicts:
# source/CMakeLists.txt
# Conflicts:
# source/glbackend/gl_texture.cpp
# Conflicts:
# source/CMakeLists.txt
# Conflicts:
# source/build/src/palette.cpp
# source/core/gamecontrol.cpp
