Add a "status" API to DiagnosticContext, overhaul Downloads console output #1869

# to view logs

Job	Run time
json-schema	1m 3s
format	2m 40s
builds / build (windows-2022, windows-ci)	3m 37s
builds / build (ubuntu-20.04, linux-ci)	1s
builds / build (macos-13, macos-ci)	7m 38s
	14m 59s

Provide feedback