Open profiles in untitled editors on complete

[connor4312]

For use with the profile visualizer.

Currently blocked on microsoft/vscode#93441 -- until then profiles will be opened up as an unfriendly wall of JSON.

[connor4312]

Untitled editors can't be opened for custom webviews. Instead we now save the profile in the workspace and open it as a normal file.

[aeschli]

Taking a snapshor was not so easy, but found an context menu item on the call stack :-)