Add support for scam protection

[CrisBarreiro]

Task/Issue URL: https://app.asana.com/0/0/1209879813659870

Description

Steps to test this PR

Feature 1

• Fresh install the app
• Using the app inspector, check that only phishing and malware datasets are present. Data needs to be downloaded, so it might take a few seconds to complete. The easiest way is to check the revisions table in malicious_sites db
• Open https://privacy-test-pages.site/security/badware/phishing.html and check it's blocked
• Open https://privacy-test-pages.site/security/badware/malware.html and check it's blocked
• Open https://privacy-test-pages.site/security/badware/scam.html and check it's not blocked

Feature 2

• Set @Toggle.DefaultValue(true) for scamProtection
• Fresh install the app
• Using the app inspector, check that phishing, malware and scam datasets are present. Data needs to be downloaded, so it might take a few seconds to complete. The easiest way is to check the revisions table in malicious_sites db
• Open https://privacy-test-pages.site/security/badware/phishing.html and check it's blocked
• Open https://privacy-test-pages.site/security/badware/malware.html and check it's blocked
• Open https://privacy-test-pages.site/security/badware/scam.html and check it's blocked
• Check m_malicious-site-protection_error-page-shown is fired with category=scam
• Accept risk and visit site
• Check m_malicious-site-protection_visit-site is fired with category=scam
• Click the omnibar icon
• Check privacy dashboard is shown normally
• Disable scamProtection under Feature Flag Inventory and restart the app
• Open https://privacy-test-pages.site/security/badware/scam.html and check it's not blocked

UI changes

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• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1209910424512874

[CrisBarreiro]

• Enable scam protection for internal users #5875
• Add separate worker for scam, so it can handle RC updates immediately #5857
• Add support for scam protection #5853 👈 (View in Graphite)
• develop

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