Add "generate_mipmap" font import option.
Add some missing features to the Sprite3D.
Move BiDi override code from Control to TextServer.
Add functions to access TextServer font cache textures.
Add MSDF related flags and shader to the standard material.
Change standard material cache to use HashMap instead of Vector.
Fix "Fill" alignment processing wrong side of the text if overrun trim was applied.
Improve "Fill" alignment to avoid adding excessive subsequent spaces or elongations.
Add font detection to the overrun, to correctly add ellipsis (was using last glyph font, which doesn't necessary have dot character).
Improve line breaking to avoid adding excessive subsequent soft break points for languages without word separator.
Port missing overrun/justification code to the Fallback text server.
Fix inferred text direction detection by controls.
Add tests for "Fill" alignment and line breaking glyph flags.
