Previously we built DevTools for all browsers with version 2 of the manifest file format.
This commit includes a number of refactors and API additions that will enable us to build DevTools with version 3 of the manifest file format.
The manifest v3 build of Angular DevTools has been tested on Chrome, Edge, and Safari.
Notably, the Firefox version of Angular DevTools remains as a manifest v2 build. Firefox does not yet support manifest v3 in it's latest stable release. When Firefox makes this transition, a follow up PR will update the Firefox manifest file to version 3.
Because Firefox still needs v2, we need to keep some old v2 APIs around in our background page (service worker in v3) that will execute conditionally based on if the extension was built for v2 or v3. This is determined with the chrome.runtime.getManifest().manifest_version API.
PR Close#47575
