Apply translations for 2.4 strings

This includes translations that were missing translations, with varying
extent between different languages, for the following things:
- "X mode is enabled" in-game warnings
- "Press {button} to freeze/unfreeze gameplay" for the level debugger
- Some credits strings for the post-2.4.0 extra Spanish options, the
  PT_BR proofread, and Persian
- The recent gamepad menu changes (#1229)

Furthermore:
- "TAB" (used in the level debugger string) is now a separate string
  instead of being hardcoded, because some languages needed it
  translated
- Added missing arrows to Arabic/Persian font (needed for the gamepad
  menu, and also a translator menu actually)

desktop_version/fonts/font_ar.fontmeta

@@ -10,6 +10,7 @@
         <range start="0xFE80" end="0xFEFF"/>
         <range start="0x0600" end="0x06FF"/>
         <range start="0xFB50" end="0xFBFF"/>
+        <range start="0x2190" end="0x2193"/>
     </chars>
     <special>
         <range start="0x064B" end="0x065F" advance="0"/>