✨ Add QuiddityAPI

This MR adds several things to the Socket.IO server:

• quiddity.create and quiddity.remove server routes, to create and remove quiddities
• subscription to on-quiddity-created and on-quiddity-removed signals and emission of quidditiy.created and quiddity.removed events to all connected clients
• Type hints for all functions
• First basic example and test file (01-basic.py), showcasing how to use the API
• CMake configuration to run tests in the CI

This is obviously still a WIP, and some tests are still missing (ie. the Network API)