Integrate multiple terminals into JetBrains IDE's

[loujaybee]

Currently, JetBrains doesn't read the commands/tasks functionality of Gitpod.

This can be worked around by using gp tasks for now, but ideally this is a first-class feature in JetBrains.

There is an issue to resolve for JetBrains https://youtrack.jetbrains.com/issue/CWM-6093 but this is reported now as fixed.

[felladrin]

Part of this issue was addressed by #10595, but to close it, we still need to:

• Update the terminal title whenever there's a change on the title running under Supervisor.
  • [JetBrains Backend Plugin] Update the Terminal Widget title whenever there's a change on the title from Gitpod Task Terminal #12142
• Close the IDE Terminal tab if Gitpod Terminal was closed remotely and emit a 'close' signal for Gitpod Terminal if the user clicks the "X" button to close the IDE Terminal.
  • [JetBrains] Task should be stopped when closing terminal tab #12126