refactor: buildengine publishes clearer state events

[matt2e]

#2937

• Module error state is now maintained, so that a changed file in one module getting successfully deployed does not get confused as "everything is good now"
• CLI status bar updates now rely on these engine events, rather than being spread across the engine code
• LSP uses EngineStarted and EngineEnded events to update status indicator
• Bring all engine status update logs to one place, to align explicit build commands and plugin triggered builds