Test: improved process picker

[weinand]

Test for #42521:

• windows @tsalinger
• macOS @gushuro
• linux @aeschli

Complexity: 3

In this milestone we've have improved the Process Picker:

• it does not only show node processes but also all processes that use the --debug or --inspector arguments (e.g. Electron's helper processes). So the picker can now deal both with process ids and inspector and debug ports.
  
• the Process Picker bumps newer processes to the top of the list.
• a new Attach to Node Process action that opens the process picker and attaches to a node process without a need for a launch config.

Verify:

• use this "attach" launch with an embedded PickProcess command:

  {
    "type": "node",
    "request": "attach",
    "name": "Attach to Process via pid or port",
    "processId": "${command:PickProcess}"
  }
  

• press F5 and verify that the picker correctly lists node.js or Electron processes with the correct arguments: all show process id, and when started with debug flags port and debug protocol is shown.
• verify that the picker shows newer processes at the top
• verify that you can attach to node.js or Electron processes if they are in debug mode (using the "--debug" or "--inspect flags")
• verify that you can attach to a node.js process even if it is not in debug mode (uses the SIGUSR1 signal mechanism).
• instead of using the launch config use the Attach to Node Process and try the same.