[Analytics Audit] Add the Discover List share button tapped event

[danielebogo]

📘 Part of: #2628

Adds the share button and the track event discover_list_share_tapped to the Discover lists

To test

• Make sure you have the tracks log enabled
• Go to discover
• Expand a list by tapping Show All
• Tap on the top right share icon
• confirm you see 🔵 Tracked: discover_list_share_tapped tracked
• Confirm you can copy or share the url
• Open another list like BCG
• Tap on the top right share icon
• confirm you see 🔵 Tracked: discover_list_share_tapped tracked
• Confirm you can copy or share the url

Checklist

• I have considered if this change warrants user-facing release notes and have added them to CHANGELOG.md if necessary.
• I have considered adding unit tests for my changes.
• I have updated (or requested that someone edit) the spreadsheet to reflect any new or changed analytics.

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 7.81 ❄️. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

Generated by 🚫 Danger

[SergioEstevao]

Event being sent correctly.