feat: Amp 86005 add session tracking bookmarklet

[justin-fiedler]

Summary

• Add session tracking to autotrack bookmarklet for test data capture
• Example session here
• Need to capture more test sessions - WIP

Usage

1. Generate the snippet.
   GENERATE_SNIPPET=true AMP_API_KEY=YOUR_API_KEY AMP_USER_ID=YOUR_USER_ID AMP_SERVER_ZONE=us yarn build
2. Copy the bookmarklet code to clipboard.
   cat packages/analytics-browser/lib/scripts/amplitude-bookmarklet.html | pbcopy
3. Create a new bookmark to the bookmarks bar in the browser. Paste the contents of step 2 for the url.
4. Go to a site you want to record data for
   a. Click the bookmark, it will install autotracking & session recording on
   b. Click buttons, links, etc
   c. Whenever you load a new page you need to do step 4a again to reinstall autotracking.

Checklist

• Does your PR title have the correct title format?
• Does your PR have a breaking change?: