Refactor loot-core/src/server/main.ts into multiple apps

[j-f1]

Several portions of this file (which defines the methods the client can call) have been split out into separate “apps” (e.g. loot-core/src/server/schedules/app.ts). We should move actions into these apps and create new ones where possible so that the main file is no longer ~2.5k lines long and can focus on things other than defining the methods.