[a11y]: Tooltip documentation changes necessary

[mbgower]

This is an omnibus ticket, summarizing key problems with the content of the Usage and Style pages for the Tooltip component. (Specific problems with tooltip implementation are captured in carbon-design-system/carbon#12921.)
Detailed considerations, edits and suggestions are captured in pdf exports of the pages: usage.pdf and style.pdf. These documents should be reviewed in detail.

The key considerations are:

• It's critical to make users understand that tooltips are for exposing the names/information of things that ALREADY take focus (in other words, one cannot click to see the tip because clicking the trigger will cause another action to happen)
• the information icon (i) should not be used with tooltips, but should be reserved exclusively for toggletip. The information on MDN supports this:

The tooltip is not the appropriate role for the more information "i" icon, ⓘ. A tooltip is directly associated with the owning element. The ⓘ isn't 'described by' detailed information; the tool or control is.

• It is recommended that Carbon remove the “Standard tooltip” guidance entirely. It’s likely to confuse everyone and perpetuate the noise
• reduce information on popover content (and on a related note, we suggest you make popover a pattern, not a component)
• It is recommended that Carbon make the definition tooltip always display on hover and focus. You could consider making it also display on click/activation (since AFAIK there is not other action associated with a defn tooltip) but it would be less likely to muff people up if it was just hover/focus. Let's make tooltip consistent for interaction, regardless of the context.
• This is a lesser priority, but Carbon could consider providing an example/implementation of a tooltip on an input. Option 4 in this demonstration provides a poor-ish example. The potential advantage of this is where you don't want the user to have to activate an inforamtion icon to toggle on more pronounced help. 👈 not a priority

[sstrubberg]

• When not to use section: The "i's" aren't tooltips. We need to change the image and update the guidance based on the differences between Tooltip vs Toggletip
• Variant section: needs reworked. Lots of Toggletip action in there.
• Lots of popover references: needs to be reworked. It makes more sense for that to be in the popover area.
• DefinitionTooltip should be default appear on hover on focus. Currently the prop has to be set to enable this.

[sstrubberg]

closing in favor of tracking through carbon-design-system/carbon#13521