Allow deferring starting of Compose apps until user action

[ethanjli]

In the 2024-10-03 PlanktoScope software meeting, @tpollina requested the ability to make Grafana not start during boot, but instead only start it when the user presses a button in the PlanktoScope's GUI. Such functionality would require us to be able to specify (perhaps via a feature flag combined with Docker Compose profiles) that a Docker Compose app associated with a package deployment should not be launched at boot, but instead should be deferred until after the user takes some manual action (e.g. pressing a button) which causes the execution of a command like forklift stage start-app or forklift stage start-app-profile (or maybe it should be in forklift host instead) which makes Docker Compose start the specified profile of the Compose app for the specified package deployment.

This functionality will need to interact correctly with Forklift's dependency checking of network services. Perhaps only nonblocking service dependencies will be allowed for a required service whose launching is deferred; otherwise, a deferred service is treated as if it doesn't exist in dependency checking.