feat: add `sdf` sprites via additional apis

[CommanderStorm]

Resolves https://github.com/maplibre/martin/issues/1075

I am not quite right if I have made everything correctly. The project has lots of places to configure things and it was not always clear where I need an Option.

~Another thing which is likely wrong: I'd assume as far as I read the blessing that should require new files... Something is really odd here => need to debug that before public review makes sense~ I fucked up the testcase a bit. This is now fixed