In "streaming brief" mode, `emit.message()` should clean the progress prefix

[tigarmo]

Bug Description

If I call emit.progress("Hi") and then emit.message("Done!"), the text that is actually shown is Hi :: Done!.

To Reproduce

Something like:

emit.progress("Hi", permanent=False)
emit.message("Done!")

part yaml

n/a

Relevant log output

n/a