Add pixels for Privacy Stats on HTML NTP

[ayoy]

Task/Issue URL: https://app.asana.com/0/69071770703008/1208936504720914/f

Description:
This change adds 2 new messages to track actions in the Privacy Stats widget
and implements usage and debug pixels for Privacy Stats.

Steps to test this PR:

1. Run the app from Xcode, set internal user state and set htmlNewTabPage feature flag.
2. Filter Xcode console by "PixelKit" subsystem.
3. Visit some websites to have Privacy Stats widget populated.
4. Click "Show More" and then "Show Less" and verify the following output in the console:

👾[Daily and Count-Fired] m_mac_new-tab-page_blocked-tracking-attempts_show-more_daily ["appVersion": "1.118.0", "pixelSource": "browser-dmg"]
👾[Daily and Count-Fired] m_mac_new-tab-page_blocked-tracking-attempts_show-more_count ["appVersion": "1.118.0", "pixelSource": "browser-dmg"]
👾[Daily and Count-Fired] m_mac_new-tab-page_blocked-tracking-attempts_show-less_daily ["pixelSource": "browser-dmg", "appVersion": "1.118.0"]
👾[Daily and Count-Fired] m_mac_new-tab-page_blocked-tracking-attempts_show-less_count ["pixelSource": "browser-dmg", "appVersion": "1.118.0"]

5. Repeat previous step and verify the following output in the console:

👾[Daily and Count-Skipped] m_mac_new-tab-page_blocked-tracking-attempts_show-more_daily ["pixelSource": "browser-dmg", "appVersion": "1.118.0"]
👾[Daily and Count-Fired] m_mac_new-tab-page_blocked-tracking-attempts_show-more_count ["pixelSource": "browser-dmg", "appVersion": "1.118.0"]
👾[Daily and Count-Skipped] m_mac_new-tab-page_blocked-tracking-attempts_show-less_daily ["pixelSource": "browser-dmg", "appVersion": "1.118.0"]
👾[Daily and Count-Fired] m_mac_new-tab-page_blocked-tracking-attempts_show-less_count ["pixelSource": "browser-dmg", "appVersion": "1.118.0"]

6. Without closing the app, call the following in terminal:

sqlite3 ~/Library/Containers/com.duckduckgo.macos.browser.debug/Data/Library/Application\ Support/PrivacyStats.sqlite 'drop table ZDAILYBLOCKEDTRACKERSENTITY'

7. Visit a website, verify the following output in the console:

👾[Daily and Count-Fired] m_mac_debug_new-tab-page_privacy-stats_database_error_daily ["e": "2", "d": "PrivacyStatsError", "appVersion": "1.118.0", "ud": "NSCocoaErrorDomain", "ue": "256", "pixelSource": "browser-dmg"]
👾[Daily and Count-Fired] m_mac_debug_new-tab-page_privacy-stats_database_error_count ["pixelSource": "browser-dmg", "appVersion": "1.118.0", "d": "PrivacyStatsError", "ud": "NSCocoaErrorDomain", "e": "2", "ue": "256"]

8. Quit the app and call the following in terminal:

echo "hello" > ~/Library/Containers/com.duckduckgo.macos.browser.debug/Data/Library/Application\ Support/PrivacyStats.sqlite

8. Launch the app, verify the following output in the console:

👾[Daily and Count-Fired] m_mac_debug_new-tab-page_privacy-stats_could-not-load-database_daily ["pixelSource": "browser-dmg", "appVersion": "1.118.0", "e": "26", "d": "NSSQLiteErrorDomain"]
👾[Daily and Count-Fired] m_mac_debug_new-tab-page_privacy-stats_could-not-load-database_count ["d": "NSSQLiteErrorDomain", "appVersion": "1.118.0", "e": "26", "pixelSource": "browser-dmg"]

9. Clean up after testing so that your debug build works:

rm -f ~/Library/Containers/com.duckduckgo.macos.browser.debug/Data/Library/Application\ Support/PrivacyStats.sqlite

Definition of Done:

• Does this PR satisfy our Definition of Done?

---

Internal references:

Pull Request Review Checklist
Software Engineering Expectations
Technical Design Template
Pull Request Documentation

[SabrinaTardio]

Works as expected!
Are the pixel permanent? should we add tests for those?

[github-actions]

	Warnings
⚠️	PR has more than 500 lines of code changing. Consider splitting into smaller PRs if possible.

Generated by 🚫 dangerJS against 2a58f70

[ayoy]

Thanks @SabrinaTardio!

Pixels are permanent. Show more/less events are tested in NewTabPagePrivacyStatsClientTests (to the point of being pushed to the event mapper - the receiver that fires pixels is trivial and doesn't need testing imo).

Database error pixels aren't tested because it's tricky to break the database in unit tests, but the events are pushed from do-catch handlers for database operations so this is again straightforward.