Detect and warn if multiple copies of React DevTools are installed #22486
Description
If you have more than one copy of React DevTools installed and enabled (e.g. the version in the Chrome store and a locally built version) they can interfere with each other.
DevTools should detect this case and warn by showing a dialog in the DevTools UI and/or by logging to the console.
Note that we should not warn if a related tool like Fast Refresh is present, only another copy of DevTools.