Add metrics to phishing warning page

[holantonela]

Background

We are iterating the current version of the phishing warning page. Ideally, we improve how we communicate the risk to users, so they decide NOT to move forward visiting the deceptive site.

Before iterating, we should implement some metrics to have a baseline for the current usage and be able to measure if the new version is indeed effective or not.

Acceptance Criteria

1. Phishing warning page event is triggered when users who have opted in MetaMetrics are prompted to it.
2. Phishing warning page link(s) event is triggered when users who have opted in MetaMetrics click on:
   2.1 Main CTA [Back to safety]
   2.2 Continue to the suspicious site [Continue to the site]
   2.3 External link to report an error in the flagging
   2.4 External link to Zendesk [Learn More]
   2.5 External link for lists providers

Metrics Checklist

• This PR observes the privacy policy defined in MetaMetrics: A Refresher on MetaMask’s Analytics System
• This PR does NOT add any new 3rd party data providers
• This PR does NOT collect token balances, IP addresses, wallet addresses, or private keys

[worldlyjohn]

All external links should trigger an event name External Link Clicked with the following properties:

• link_type: Phishing Detection
• url_domain or url: if url may be sensitive, like a token tracker, then only store domain and use url_domain. if url is a generic/common page then full url is ok and use url.
• location: page where exists
• chain_id: chain id in hex
• category: Navigation

For the page event, we want to confirm that we are sending the url of the offending site

[bschorchit]

All external links should trigger an event name External Link Clicked with the following properties:

• link_type: Phishing Detection
• url_domain or url: if url may be sensitive, like a token tracker, then only store domain and use url_domain. if url is a generic/common page then full url is ok and use url.
• location: page where exists
• chain_id: chain id in hex
• category: Navigation

For the page event, we want to confirm that we are sending the url of the offending site

Hey @worldlyjohn , I'm grooming this to work on these new metrics with PS team and I have couple of comments/questions here:

• link_type: Phishing Detection - Should we use snake case here? phishing_detection instead of Phishing Detection for the value.

• location: page where exists - for this case, will this info be repetitive with the link_type one? Because it will also refer to phishing detection/ phishing warning page. But I understand we might want to keep both to have the same properties as other External Link Clicked have.

• chain_id: chain id in hex - Is chain_id information really useful here? The user is trying to open a new dapp when this page gets displayed it doesn't mean their MM is already reflecting the chain that that dapp uses.

For reference, I'm grooming this here.

[bschorchit]

link_type: Phishing Detection - Should we use snake case here? phishing_detection instead of Phishing Detection for the value.

Update: I proposed this to be the possible values (see below), happy to iterate on the exact naming.
link_type: learn_more | report_wrong_detection | continue_to_site | back_to_safety

I do see on Mixpanel that the other External Link Clicked are not using snake case, any reason for that?

[bschorchit]

Any recommendations of name or properties for the event that will be fired when we the phishing warning page gets displayed? Already added the url property.

[worldlyjohn]

@bschorchit

• link_type: yes on snake case. this event should use a single property value for link_type. other link types might be "customer_support" or "block_explorer".
• location: yes it can be repetitive. the purpose was for something like "contact support". we might want to know what page they are finding this from (home vs a secondary page)
• chain_id: not necessary as you suggest.

link_type: learn_more | report_wrong_detection | continue_to_site | back_to_safety

i'm not sure this is at the right level, but rather secondary descriptors of the link_type=Phishing Detection, right?