Double-wide glyphs should make use of the double-width

[slavfox]

Right now all the glyphs in Cozette are limited to the 6x13 bounding box. While this is cool for glyph map generation and whatnot, it leads to extraneous spacing whenever a double-wide glyph is drawn, like the 🐍 in my prompt:

build.py should probably be extended with glyph linting capabilities, so that it can warn about single-wide glyphs for double-wide codepoints, and oversize glyphs for single-wide codepoints.

[octoshrimpy]

within KDE's Kate, some symbols don't respect the double-width:

top: with space as padding; bottom: no spaces between symbols

would it be a good idea to center the glyphs that use double-wide within the 26px spacing they have available?

[slavfox]

All the glyphs from the screenshot, and all the double-wide glyphs that have been added since this issue was opened, are centered within their double-wide bounding boxes.