What?

Replaces the legacy TabPanel component with the new Tabs component.

Why?

Part of the work outlined in #52997

How?

TabPanel is replaced by Tabs and its sub-components.

Testing Instructions

1. Create a new post
2. Click on the Options button in the top right corner, then Preferences at the bottom of the menu that opens
3. Test the tabs (this set is aligned vertically, unlike other similar, recent PRs), confirming that their appearance and behavior matches trunk

Testing Instructions for Keyboard

Screenshots or screencast

1. Make sure your browser window is full-height, and your devtools are not open in a way that shortens the heights of the viewport. Scroll behavior will impact some of these tests.
2. Create a new post
3. Use Tab to navigate across the top toolbar to the Options button on the far right, and press Space to activate it.
4. ArrowDown to the Preferences option and once again press Space to activate it.
5. Assuming the General tab (which should be displayed by default) is not scrollable, confirm that pressing Tab cycles thought the Close button, then over to the General tab itself, and then to the first toggle being displayed in the tab contents. From there, Tab should navigate through all of the displayed toggles for this tab.
6. Now, using Shift+Tab, confirm that the opposite focus is applied in the opposite order. Reversing through the contents of the tabpanel, then to the General tab itself, then to the Close button.
7. Confirm that during that during all of this, the tabpanel itself does not get a tab stop, nor does the wrapper around the contents of the PreferencesModal.
8. Tab or Shift+Tab back to focusing on the General tab.
9. ArrowDown to the Blocks tab, which has a lot more content and should be scrollable.
10. Repeate the above Tab and Shift+Tab tests. This time, because the tab is scrollable, the Modal contents wrapper should get a tab stop between the last element in the tabpanel contenst and the Close button. Effectively, focusing the Close button and pressing Shift+Tab should focus the wrapper. Pressing Shift+Tab should go to the last toggle of the currently displayed options.