Don't add the default font if user-selected font is used

[Teascade]

Somehow, if a user sets a custom font to the terminal, don't include the default font in, this just adds useless data to the build.

Currently the default font exists even if the user uses a custom font, but this should not be.

Fix proposal:

~Make the default font a default feature, and by making it a feature, it you can simply add a flag to not compile it in.~

EDIT: A Better solution: Make a macro-solution, so that with macros it is possible to determine weather the default font should load or not. Perhaps prevent_default_font!(), to prevent compiling the default font?