Add feature to completely disable any texture filtering (LINEAR_PATCH takes care only for additional ones, while the core ones are hardcoded)

[Arthandas]

• If I unpack the game files the fields are pixelated no matter the LINEAR_PATCH setting.
• World textures are pixelated only when LINEAR_PATCH=1
• Enabling LINEAR_PATCH disables the fxaa/smaa antialiasing settings

[MaKiPL]

Yes- The LINEAR_PATCH flag actually takes care of disabling the linear filtering on more glTexParameters, however the core of the core engine automatically applies the point-clamp filtering to other functions. So there's currently no way to completely disable the linear filtering disable. I'll change that issue to be more like adding an option to completely (100%) not touch any filtering and replace the LINEAR_PATCH to be an actual LINEAR_PATCH setting