* Remove the 'app' domain from flutter daemon
By default the daemon won't register the "app" domain, you need to opt-in (which the 'run' command does, as well as the tests for the app functionality).
Fixes#6658.
* Tweak text
* Put restart/callServiceExtension/stop back into daemon mode
* Add a comment about removing discoverApps
* Send an event at startup with the protocol version and pid
The pid will help with some of the issues of terminate the process when launched through a shell script and the version will allow clients to make decisions about supported features.
I've also bumped the protocol version number for two reasons:
1. This change
2. We didn't increase it when we added the previous emulator commands
Eliminates the need for the device/daemon code to get at the iOS/Android
tooling indirectly via Doctor. In tests, we now inject the workflow
objects (or mocks) directly.
