Update "Network features reference" including "Filter requests" (#3405)

* date

* detailed toc > notes

* update structure

* throttling article add

* panel tool

* some "clean up"

* update throttle menu

* mark todo's for Filter Request sections

* revert Throttling

* 8 pngs

* the More filters dropdown

* add two in Detailed Contents

* Throttle WebSocket connections

* Create a custom throttling profile

* linkfix

* filter pngs

* initial placeholder pngs

* old experiment

* fix 15 of 30 todos

* big rows

* unique alt text

* piesocket registered

* de-dup custom throttle steps

* label 2 PieSocket pngs

* clarif png lead-ins

* api token

* Replay XHR request

* Group requests by inline frames

* Display query string parameters

* Analyze events in a stream

* finalize Query String Parameters

* View payload source - png

* Copy network requests to the clipboard

* Inspect Network Activity demo

* apply review except 9 comments

* Analyze the messages of a WebSocket connection

* blocked response cookies, Addr bar

* Show only blocked requests

* View HTTP header source

* View payload source

* Display URL-encoded query string parameters

* Copy stack trace > XHR

* not npx

Author: mikehoffms