Fix browser extension e2e tests
Created by: felixfbecker
Browser extension github.com E2E tests were failing on my attempt to release #6546. This fixes them, and gives them some love.
- Changed GitHub e2e tests to use the e2e Driver
- Moved Firefox code into the driver init code
- Move types to shared/ and use recommended way to define custom types
- Add shared blob page tests from other code hosts
- Rewrite PR page tests to be less flaky
- Reenable Firefox e2e tests
- Remove old fork of
web-ext
- Add VS Code debug config for e2e tests
I recommend reviewing in split mode with ignored whitespace