feat(History): Add expandable sections

[rebeccaalpert]

API is somewhat tortured.

Fixes #864.

[patternfly-build]

Preview: https://chatbot-pr-chatbot-879.surge.sh

A11y report: https://chatbot-pr-chatbot-879-a11y.surge.sh

[thatblindgeye]

In addition to the file comments below:

• This can be done in a separate PR since it's pre-existing, but each MenuGroup should be aria-labelledby referencing the visible text label of the group (
• For the show less/all button, that should probably follow the focus management in the "vieww more" Menu example where focus goes to the menuitem that replaced the "show all" button (in the new example in this PR, "Red Hat Certification"). When clicking the "Show less" button, focus should remain on the button as it updates to "Show all", though.
• It sorta feels a little odd that the "Saved prompts" toggle needs to be Tabbed to in order to expand it, but its contents become part of the general menu item navigation via up/down arrows keys. It almost feels like an entirely separate menu of things that should have its own menu navigation, but visually it looks like any other group of history items that can be navigated to via just up/down arrow keys. One thought was that the toggle should be a menuitem itself, but we don't typically do that for menu group titles.

[rebeccaalpert]

Addressed feedback!

[thatblindgeye]

• Since we're adding some aria-labelledby logic already in this PR, let's also add the logic to label the actual Menu's by the MenuGroup text label as well. End result should be the pf-v6-c-menu element has aria-labelledby referencing the ID of the pf-v6-c-menu__group-title element.
• Rather than an expandable group being part of the same Menu component as the other groups, wdyt about having them be their own unique Menus? So instead of Menu > Pinned group, Chat group, Saved Prompts group, it's Menu > Pinned group, Chat group followed by Menu > Saved Prompts group? Then we don't necessarily need to autofocus the first item of the exapnded menu (Tabbing to the first item instead), and possibly it feels a little less odd that there's an expandable toggle in the middle of navigating between all the menuitems (since all the groups are part of the same Menu instance); instead you only are ablw to arrow through non-expandable menu items even when there's multiple groups, and you can only arrow through menuitems within that specific expandable menugroup

[thatblindgeye]

Just some lint issues needing fixing