Windows terminal session names don't change when launching a shell from the initial shell

[Tyriar]

Running cmd.exe inside powershell for example will always show powershell.exe as the terminal session name in the dropdown.

See #29879 (comment) for a possible solution utilizing wmic.exe.

Follow up: #30070

[Tyriar]

The eventual solution here will probably involve a combination of caching, polling and throttling calls to wmic, utilizing knowledge we can pull from the terminal like whether any output has happened (ie. there's no point checking if nothing has changed). Even though they're short-lived processes, we need to be very careful about not doing this too much.

[Tyriar]

I think for the case of executables we should trim the .exe. We don't gain much by saying "powershell.exe" over "powershell".

[Tyriar]

@Lixire I guess the next steps on this one are to make another call to wmic ~100ms after onData fires, but reset the timer if onData is fired again. We're after this behavior:

when onData fires
  if the timer is an active timer
    reset it to 100ms
  else
    create a timer for 100ms, when it goes off get the shell name as we are on enter

After this is done we will cover all major cases I believe. We'll be checking on enter, just after a program is launched, and also when output stops streaming in, for example when a process ends and the regular prompt is displayed.