External fonts support, additional glyph ranges

[gandalfthewhite19890404]

Validation

• I've read the FAQ.
• The Xenia build used is from the master branch (not MLBS/AlexVS/Canary/pull requests, etc.)
• This issue isn't for tech support (help with Xenia).
• If this issue occurs in a specific game, I've done analysis to locate the faulty subsystem of the emulator and a potential reason in it.
• I've checked if this issue hasn't already been reported.
• My device meets the minimum requirements: https://github.com/xenia-project/xenia/wiki/Quickstart#system-requirements
• (If building) I have read the building doc: https://github.com/xenia-project/xenia/blob/master/docs/building.md

Describe what's going wrong

Currently emulator supports only Latin and Basic punctuation font glyphs.

Describe what should happen

You can extend glyph ranges by modify emulator's sources alternative font constant.
Why not bundle freeware fonts with emulator or let users decide what font he wants to use?

Also, please add these glyph ranges for future usage:

0x0370, 0x03FF, // Greek
0x0400, 0x044F, // Cyrillic

If applicable, provide a callstack here, especially for crashes

No response

If applicable, upload a logfile and link it here

No response