Fix: Hide Pages menu for users with insufficient roles

[dvdchr]

Fixes #19885

This PR hides the Pages menu item from the Site Menu when the user has no edit_pages capability. As for XML-RPC access, we only check whether the user is an admin of the site (marked by the isAdmin boolean field). This matches how it's currently implemented in Android:

https://github.com/wordpress-mobile/WordPress-Android/blob/1dd182a56f1df4ba168c6750db866484370bf14c/WordPress/src/main/java/org/wordpress/android/ui/mysite/items/listitem/SiteListItemBuilder.kt#L119

Caveat: Editor accounts via XML-RPC will lose access to the Pages menu because 1.) editors aren't admins, and 2.) we currently do not pull any role information from the XML-RPC sync processes. Perhaps this is something to explore in the future.

To test

Follow the setup below, and verify the Pages menu visibility in My Sites > Menu.

Account type	Role	Pages menu
WordPress.com	Admin	👁️ Visible
WordPress.com	Editor	👁️ Visible
WordPress.com	Author	🚫 Hidden
XML-RPC	Admin	👁️ Visible
XML-RPC	Editor	🚫 Hidden1
XML-RPC	Author	🚫 Hidden

Regression Notes

1. Potential unintended areas of impact
   See the caveat above about XML-RPC Editor roles.

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   Manually tested the changes.

3. What automated tests I added (or what prevented me from doing so)
   N/A.

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

Footnotes

1. Note that this is a known issue. The current XML-RPC implementation only allows us to see if the user is an admin, but there's no information about the current user. ↩

[wpmobilebot]

You can test the changes in WordPress from this Pull Request by:

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• Then installing the build number pr20287-6c170b3 on your iPhone

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[wpmobilebot]

You can test the changes in Jetpack from this Pull Request by:

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• Then installing the build number pr20287-6c170b3 on your iPhone

If you need access to App Center, please ask a maintainer to add you.

[wargcm]

LGTM

[dvdchr]

Thanks @wargcm !