Boards UI update and add support for private boards

[chainchompa]

Summary

Update Boards UI in the gallery and adds support for creating and displaying private boards

Related Issues / Discussions

QA Instructions

Can view private boards by setting config.allowPrivateBoards to true

Merge Plan

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Tests added / updated (if applicable)
• Documentation added / updated (if applicable)

[psychedelicious]

Thanks! I did a styling pass and fixed a few edge cases (see commit messages). Simplified a lot of the markup while retaining the same overall layout.

There are a number of things I'd like to iterate on but didn't get to.

1. When the board name is long, it's hard to select the board without editing the name. Some ideas:

• Make it edit on double click. I couldn't figure out how to programmatically start editing the <Editable /> component - maybe using the useEditableControls hook? Might need to be a custom component. Not sure I like this really anyways.
• Use the example in the chakra docs for having a separate button that starts editing.
• Use a modal to rename boards and remove the click-to-edit functionality.

2. This UI is getting thicc:
   
   Seems really chunky. Before the gallery changes, you could minimize it to just two rows - board name and the images/assets buttons. Now it's a minimum of 5 rows - 6 (!) if you have private boards. Feels like way too much. Most of the time, I don't care about any of the rows.

3. When searching boards, we don't hide the uncategorized board. Maybe we should?

4. When you add a board, it doesn't clear the search term. Unless you are lucky with your search term, the newly-created board doesn't show up and it seems like no board was added.

5. Unrelated to this PR, but I was adding a lot of boards to test and then it was a pain to delete them one-by-one via the context menu.

6. The image count starts cramping each row when the board name is long, so I removed the word "images". We could use a container query to conditionally render that extra word depending on the container's width.

I don't think these should be blockers for this PR.