Update site title when it changes from site settings

[Gio2018]

Fixes #18484

This PR fixes an issue that prevented the site title in My Site to be updated when it changed from site settings

To test:

• checkout/build/run this branch
• Go to My Site -> Site Setitngs
• Tap on Site Title and update the existing title
• Navigate back to My Site, and ensure that both the site title and the navigation bar title reflect the new title
• Still on My Site, tap on the site title, and update the title
• Make sure that:
  • The spinner appears on the site title while the update is in progress
  • The title is correctly updated when the spinner stops
  • The notice of update title appears at the bottom of the screen (see screenshot below)

updates from Site Settings	Updates from My Site

Regression Notes

1. Potential unintended areas of impact
   None

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

3. What automated tests I added (or what prevented me from doing so)
   None
   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.

[twstokes]

LGTM @Gio2018 - it works as described. Great work! 🎉

I also tested for any regressions related to this issue and found none.

One minor non-blocking observation. There's a brief flash of the title going from an empty string to the new one which is more noticeable when changing the title directly from the modal. I didn't dig to see how complex it would be to smooth that out, but thought I'd bring it up.

Video	Screenshot
Simulator.Screen.Recording.-.iPhone.13.-.2022-05-09.at.18.02.17.mp4

[Gio2018]

Thank you for reviewing @twstokes !

There's a brief flash of the title going from an empty string to the new one which is more noticeable when changing the title directly from the modal

If I understand this correctly, I believe it depends on this code: I think we can leave as it is, because if the connection is not that fast, the spinner might take longer to disappear and it does make sense to blank the underlying title momentarily.