[react-dom] Provide a way to silence devtools recommendation

If you hit this console message and search for how to turn it off, many people recommend hacky ways to do so that also end up breaking the extension if you actually want to use it later on.

This provides a way to turn off just the message, without trying to trick injectIntoDevTools into thinking something's happened.

packages/react-dom/src/client/ReactDOMClient.js

@@ -57,7 +57,7 @@ const foundDevTools = injectIntoDevTools({
 });
 
 if (__DEV__) {
- if (!foundDevTools && canUseDOM && window.top === window.self) {
+ if (!foundDevTools && canUseDOM && window.top === window.self && !window.__DONT_RECOMMEND_REACT_DEVTOOLS__) {
  // If we're in Chrome or Firefox, provide a download link if not installed.
  if (
  (navigator.userAgent.indexOf('Chrome') > -1 &&