Added support for badge_shader field in mod.json.

[AllUniversal]

+Title, this allows more easily having mod badge shaders.

! If this is merged, #1423 should probably be looked at and fixed.

Additional Info:

• I didn't modify api's or I've made a PR to the wiki repo.
• I didn't modify api's or I've updated lsp definitions.
• I didn't make new lovely files or all new lovely files have appropriate priority.