bext: track browser extensions installs and uninstalls
Created by: erzhtor
Part 1 of https://github.com/sourcegraph/sourcegraph/issues/31486
This PR:
- Adds
BrowserExtensionInstalled
event for browser extension installs (non-dev version) - Adds UTM parameters for browser extension uninstall link
Test plan
yarn --cwd client/browser build
- Reinstall browser extension locally
- Open background script dev tools and check that there is a console log message
Triggered "BrowserExtensionInstalled" using
- Uninstall browser extension and check that after install page
https://about.sourcegraph.com/uninstall/
has UTM parameters. NOTE: UTM parameters are quickly stripped after page load.