Stop workflow engine

It would be good to be able to stop the workflow engine, e.g. through a setting or even a single line of code.
The challenge would be that there are various components like Quartz and Hangfire hosted services that keep on triggering workflow executions.

Start by locating the workflow engine's Quartz and Hangfire hosted services, since the issue identifies them as components that trigger executions. Determine how a setting or single line of code could stop the engine while preventing those hosted services from starting or triggering workflows. Done means the engine can be stopped through the requested control and no workflow executions are triggered afterward.

Written by the indexing model from the issue text.