Output with category="important" is displayed in modal dialogs #24
Description
This is the specific user issue that we're dealing with in the debug adapter for Python:
microsoft/debugpy#981
The root cause is that the debugger sends a notification about a long-running value computation as an "output" even with "category" set to "important". On other clients that we're aware of, most notably VSCode, this causes a pop-up non-modal notification to appear - this is the desirable behavior from our perspective, because printing it to the debug console was not sufficiently discoverable by the users whenever they hit this issue.
Thus, to accommodate VS without regressing experience for other clients, as things are, we'll have to do clientID sniffing, unless VS also switches to non-modal UI here.