Add support for email protection logout

[alistairjcbrown]

Reviewer: @jonathanKingston

Description:

Task: https://app.asana.com/0/0/1202050175851755/f

Allows the extension to communicate supported capabilities to the Email Protection web app, as well as support the web app requesting sign out.

Steps to test this PR:

1. Checkout this branch and run npm run release-chrome
2. Open Chrome, and load the extension build
3. Go to https://duckduckgo.com/email/settings and log in
   • Confirm that the extension has email autofill enabled by going to the extension settings
4. A "Sign Out" button should be visible at the bottom of the Email Protection settings page
5. Click the "Sign Out" button -- you should be logged out of the settings page
   • Confirm that the extension has email autofill disabled by going to the extension settings

Automated tests:

• Unit tests
• Integration tests

Reviewer Checklist:

• Ensure the PR solves the problem
• Review every line of code
• Ensure the PR does no harm by testing the changes thoroughly
• Get help if you're uncomfortable with any of the above!
• Determine if there are any quick wins that improve the implementation

PR Author Checklist:

• Get advice or leverage existing code
• Agree on technical approach with reviewer (if the changes are nuanced)
• Ensure that there is a testing strategy (and documented non-automated tests)
• Ensure there is a documented monitoring strategy (if necessary)
• Consider systems implications

[jonathanKingston]

LGTM I'll test tomorrow. Thanks

[alistairjcbrown]

@jonathanKingston Updated to latest autofill. Any changes required for this PR?

[jonathanKingston]

Nope all good, thanks for version bumping here :)