[Bug] Run Tasks in Control Panel doesn't run all tasks

[cmsj]

RomM version
latest official Docker image

Describe the bug
In Settings -> Control Panel there's an option to Run All the scheduled tasks, but it doesn't currently do that

It tries to update MAME XML (which isn't a task currently defined in the codebase, I submitted a PR to remove this: #836), updates the Switch TitleDB, but doesn't run the scheduled rescan.

It might also be helpful to be able to manually run available tasks individually.