[MPP-1708] Popup Refactor (Epic PR to Main)

[maxxcrawford]

Summary

Refactor the add-on panel to generate masks and better manage/leverage the Relay experience. This is an epic PR, comprised of other reviewed PRs. Please follow the commits and look at past PRs for specific feature testing steps.

Links:

• Jira Epic: https://mozilla-hub.atlassian.net/browse/MPP-1708
• https://mozilla-hub.atlassian.net/browse/MPP-1712
• https://mozilla-hub.atlassian.net/browse/MPP-1713
• https://mozilla-hub.atlassian.net/browse/MPP-1714
• https://mozilla-hub.atlassian.net/browse/MPP-1715
• https://mozilla-hub.atlassian.net/browse/MPP-1716
• https://mozilla-hub.atlassian.net/browse/MPP-1717
• https://mozilla-hub.atlassian.net/browse/MPP-1769
• https://mozilla-hub.atlassian.net/browse/MPP-1770
• https://mozilla-hub.atlassian.net/browse/MPP-1771
• https://mozilla-hub.atlassian.net/browse/MPP-2814
• https://mozilla-hub.atlassian.net/browse/MPP-2819
• https://mozilla-hub.atlassian.net/browse/MPP-2859
• https://mozilla-hub.atlassian.net/browse/MPP-2860
• https://mozilla-hub.atlassian.net/browse/MPP-2863
• ~L10N PR: https://github.com/mozilla-l10n/fx-private-relay-add-on-l10n/pull/44~
• Figma

Caveats:

There are two missing features from this release:

1. CSAT Survey
2. Manage Mask Panel (Update Promo Block Level)

Review notes:

• Ignore the diff with popup.html/js/css files. They were started from scratch.

Testing Scenarios:

• By tier: Free, Premium, Phones, Bundle
• By browser: Firefox, Chrome, Firefox for Android
• By geolocation: US/CA (Phones), Premium-country, Wait-list country
• By language (Confirm localization)