tile Scheduler should error if its name is not unique

[adam-ce]

i.e., Scheduler::Scheduler(std::string name, unsigned int tile_resolution, QObject* parent) should get a static registry of names, if the name exists, assert false in debug mode, otherwise write to the log and disable the scheduler.

https://github.com/AlpineMapsOrg/renderer/blob/main/nucleus/tile/Scheduler.cpp