[Menubar] Adds keyboard behaviors to the menubar, improves accessibility

[tespin]

Progresses #2933

Just setting this up to track next steps for the component! This PR focuses on adding proper keyboard behaviors to the recently refactored Menubar. Currently in progress

• Implement keyboard behaviors
  • top level menu items are navigable
  • submenus are navigable
  • character search to jump to items
  • mouse behaviors are synced
• add proper styling for focused items
• Tests
  • unit tests
    • Menubar.jsx
    • MenubarItem.jsx
    • MenubarSubmenu.jsx
  • test with screen reader
  • state management tests
  • verify focus management and keyboard navigation
  • test across different OSs
    • apple
    • windows
    • linux
  • browser testing
    • chrome
    • firefox
    • safari
    • edge
    • brave
    • opera

Changes (as of 1/17/25):

• top level items are navigable
• ButtonOrLink has been setup with ref forwarding for focus management
• Logo was extracted into its own component and moved out of the Menubar

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123

[tespin]

• Extract logo to header level for better semantic structure
• Ensure arrow keys only cycle through menu items, excluding the logo