Theia: [task] disallow running identical tasks

[vince-fugnitto]

Description

Should we disallow identical tasks from running at the same time?
Currently, we can execute multiple versions of the same task simultaneously which be error prone.

In vscode, only one instance of a task can be active at a given time, and users are prompted to either Terminate or Restart the task or cancel the action.


Should we do the same?

[akosyakov]

@vince-fugnitto as usual, aligning with VS Code sounds good

[akosyakov]

Also if a task is finished but we run it again then we should reuse the terminal. in VS Code:

Notice notes in the terminal about which task is executed and that the terminal will be reused. It would be good do the same.