Add OpenTelemetry integration

[KallynGowdy]

:rocket: Features

• Added OpenTelemetry tracing to the CasualOS server.
  • This will greatly improve our ability to track down issues and understand what is going on with the system.
  • Can be configured via the SERVER_CONFIG environment variable in the telemetry key.
  • See the SERVER_CONFIG schema in ServerBuilder.ts for more information.

Closes #490