[Analytics Hub] Store views for SiteVisitStats (Storage)

[rachelmcr]

Part of: #8363
⚠️ Depends on #8386 ⚠️

Description

This PR is a followup to changes to Networking in #8386. Now that we are requesting views when we get SiteVisitStats, this PR updates the Storage layer so we store them (as part of SiteVisitStatsItem).

We don't strictly need this storage support for the Analytics Hub (we aren't planning to store data from those requests or fetch data from storage) but I'm adding it for completeness since we already store these stats items and use them elsewhere in the app.

Changes

• Adds a new Core Data model 79.
• Adds a views attribute to the SiteVisitStatsItem entity in storage.
• Updates the corresponding ReadOnlyConvertible and CoreDataProperties, and unit tests.

Note: Most of the lines of changes in this PR are the new Core Data model, but the only change in the new model is the new attribute.

Testing

This views attribute is not yet used in the app, so confirm unit tests look as expected and still pass.

Submitter Checklist

Update release notes:

• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[wpmobilebot]

You can test the changes from this Pull Request by:

• Clicking here or scanning the QR code below to access App Center
• Then installing the build number pr8387-3935f3c on your iPhone

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[ealeksandrov]

LGTM