Add a "status" API to DiagnosticContext, overhaul Downloads console output #1868

# to view logs

Job	Run time
json-schema	1s
format	3m 18s
builds / build (windows-2022, windows-ci)	4m 11s
builds / build (ubuntu-20.04, linux-ci)	4m 15s
builds / build (macos-13, macos-ci)	1s
	11m 46s

Provide feedback