[Extensions] Improve error for inactive window in openPopup() API.

Calling the `action.openPopup` API for an inactive window is not
supported. Show a more specific error message in this case to make it
easier for developers to troubleshoot.

Bug: 345640558
Change-Id: Ied0f07bf073cbc3215d64c8cf828e5a9a7e21dec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5604451


Reviewed-by: Emilia Paz <emiliapaz@chromium.org>
Commit-Queue: Oliver Dunk <oliverdunk@chromium.org>
Reviewed-by: Tim <tjudkins@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1312655}