[User Sync] UI/UX Improvements

[vikrampm1]

As a follow up to 1.9.0 release, we want to update the User Sync feature with the following tweaks:

• Add a sentence or two at the top of the User Sync settings page that better explains what the User Sync feature does or is intended for. It’s fairly straightforward based on the existing settings, but some users may still be confused and not fully understand the feature.

• Add an auto scroll back to the top of the page after the sync process has completed. Currently, if a user is still on the settings page, the status message goes away and a success message shows. This message is at the top of the screen, and isn't immediately visible if the user is scrolled down.

• Update the admin notice with a link to the sync errors table below (if there are any). Currently, we display those in a table at the bottom of the settings page, but it's not clear they exist unless someone scrolls down.