Replace URL title tags with Tippy tooltips

As discussed on CZO, we should replace the title tags that show the URL on named links with Tippy tooltips, with no delay.

This will help users notice when the URL for the link is not one they expect.

• For internal links that are already in the standard format (#channel, #channel > topic, or message links like #sandbox > blue nas de-duping @ 💬), and point to the expected place, no tooltip at all (no additional info to communicate).

• For internal links that aren't in the standard format (e.g., "said" links in quote-and-reply, or whatever other label a user chooses, or #channel1 that actually points to #channel2, etc.), let's try explaining where the link goes, not the URL:

  Go to {canonical format for location}

  We should try having no delay on these tooltips.

Notes

• This is most important to do in the message feed, but we could also do it in drafts, compose box previews, etc. as a follow-up.

CZO thread