Add FA (Persian) Locale

Add RTL text support for all section of godot engine.
for use rtl text in godot engine import a font that contains arabic
glyphs and use that for editor font or gui font. (godot default fonts
not contains arabic glyphs)

Update from original

Create new bidi class and use that in text rendering.
and fix some bugs.

fixe earab (fatha,kasra,shada,...) positions and nsm type in start of
paragraph problem.
add some comment for license.