[notifications] implement "danger" for errors and "warning" for warnings

This way errors are red, warnings are yellow.
3 jobs for dev-support-emitting-warnings in 28 minutes and 33 seconds (queued for 9 minutes and 2 seconds)
latest
Status Job ID Name Coverage
  Check Lint
passed #18720
check-lint

00:10:16

 
  Compile
passed #18721
compile

00:10:22

 
  Test
passed #18722
test

00:07:54