[Stats Refresh] Insights tabbed cards: fix displaying details view

[ScoutHarris]

Ref #11360

This changes the Insights tabbed cards, Comments and Followers, to use UITableViewCells instead of one UIStackView.

Previously, all the data was stuffed into the stack view on the TabbedTotalsCell card. Now it only uses the TabbedTotalsCell card to show the header via the new DetailSubtitlesTabbedHeaderRow. The stack view is left empty. Instead, a UITableViewCell is added to the table for each data row via DetailDataRow.

There should be no visual or functional changes, but showing the details view is a lot faster. To note, there is still no loading view, so there may still be a blank view for a couple seconds for longer periods.

To test:

---

• Go to Stats > Insights > Comments on a very active site.
• Select View more.
• Verify the data appears relatively quickly.
• Verify selecting an Author row does nothing.
• Verify selecting a Post/Page row shows a web view.
• Verify selecting the filter tabs updates the data accordingly.

---

• Go to Stats > Insights > Followers on a very active site.
• Select View more.
• Verify the data appears relatively quickly.
• Verify selecting a row does nothing.
• Verify selecting the filter tabs updates the data accordingly.

---

Update release notes:

• If there are user facing changes, I have added an item to RELEASE-NOTES.txt.

[danielebogo]

Hey @ScoutHarris ! Everything looks good and works perfectly!
Well done!