Bug cleanup in Run by Line

[DavidKutu]

High priority

• context keys are sometimes stuck in the "running" state
  • Seems that we run the cell but don't hit the breakpoint, and don't reset the keys. See logs below
• RBL button doesn't show up sometimes
• Sometimes I am blocked by an error with starting the kernel. I get a modal error about a missing debug adapter, and an infinite "Starting run by line" notification
• When stepping over a call to another file, the other file is still opened
  • don't send stopped events to vscode when we're outside the notebook. Check stacktrace request to see if we get response right away.

Lower priority

• show the "starting run by line" notification only the first time
• set global context keys based on active editor, so I can run two RBL sessions in two notebooks
• Context keys are reset when any other debug session ends
  • debug.onDidTerminateDebugSession, check for our own sessions
• setting for optionally showing variable explorer

[roblourens]

worked.log
didntwork.log