[TabGroupSync] Create page action for Collaboration activity

Add a page action that will display a Collaboration Message, if one
exists in CollaborationMessagingTabData for this tab.

The page action adds a callback to the CMTD that will be notified if
the message changes while the tab is visible.

On Desktop, CHIP messages from the MessagingBackendService are
dismissed when the tab is activated and then inactivated. That is,
messages will be visible while you're visiting the tab that has one,
and dismissed once you leave that tab.

Since these messages are ephemeral, the label is always visible. The
icon contains little information about the collaboration activity
since it is just the avatar of the member that made the change.

Bug: 370924463
Change-Id: I8d13538085f0938d399fca0775dd1b898627650f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6077914
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Darryl James <dljames@chromium.org>
Commit-Queue: Mickey Burks <mickeyburks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1396879}