Window.open() complete overhaul (#12425)

* Fixes #4583

* Apply suggestions from code review

Co-authored-by: Joe Medley <jmedley@google.com>

* Update files/en-us/web/api/window/open/index.md

Co-authored-by: Joe Medley <jmedley@google.com>

* Update index.md

* Removed deprecated UI features

* Restored content

Restored best practices, FAQ and notes sections for later consideration through a new issue. Retained the removal of the tutorials and references sections since links were broken and the tutorials were painfully out of date. (not sure if I restored this correctly, so forgive my naivety if I didn't)

* Apply suggestions from wbamberg review

Co-authored-by: wbamberg <will@bootbonnet.ca>

* responses to wbamberg comments

* Update files/en-us/web/api/window/open/index.md

Co-authored-by: wbamberg <will@bootbonnet.ca>

* Reinstate addition from PR 13648

Co-authored-by: Joe Medley <jmedley@google.com>
Co-authored-by: wbamberg <will@bootbonnet.ca>

files/en-us/_wikihistory.json

@@ -86396,18 +86396,6 @@
       "Anonymous"
     ]
   },
-  "Web/API/Window/open/Obsolete_features": {
-    "modified": "2020-03-20T01:29:55.063Z",
-    "contributors": [
-      "arai"
-    ]
-  },
-  "Web/API/Window/open/Privileged_features": {
-    "modified": "2020-03-20T01:30:35.736Z",
-    "contributors": [
-      "arai"
-    ]
-  },
   "Web/API/Window/openDialog": {
     "modified": "2020-10-15T21:14:01.242Z",
     "contributors": [