I originally felt it was necessary to create a new component, MiniTooltip, to be a drop-in replacement for @mui/material/Tooltip, since it's more opinionated about styles. But while writing MiniTooltip.stories.tsx, I noticed how similar it is to our existing tooltip component. Now I'm torn:

MiniTooltip's main differences from Tooltip

• 0 delay before appearing (same as MUI tooltip)
• max width of 300px
• includes option to add Radix's Tooltip.Arrow

reasons to keep MiniTooltip

• don't want to introduce a tooltip delay to users where there wasn't one previously
  • the pro-Tooltip solution to this is to just set delayDuration={0} on all of the MUI tooltips being replaced

reasons to just use Tooltip instead

• encouraging devs to use a single component / mental model for this purpose creates a more consistent DX
  • don't want to introduce friction during development: "Should this tooltip be a Tooltip or a MiniTooltip?"
• these MUI tooltips usually contain short text, which isn't enough to hit the 300px max width
• tooltip arrow is only used in one place (TemplateInsightsPage), so we can add Tooltip.Arrow there as a one-off

...Actually I'm not so torn now that I've written the above. The existing Tooltip is looking like the winner to me, so I'll have some further changes to make to this PR.

Updated this PR to include #20869 from main. Thanks @jaaydenh!