Add Sandcastle settings

[jjspace]

Description

This PR:

• Implements Sandcastle settings using local storage
  • Theme (which already existed)
  • Editor font + ligature option
    • I included 3 popular code editor fonts for now, adding more is easier. Droid Sans is the "default" for monaco even though they don't bundle it
  • Default starting panel, gallery or editor
    • When loading a specific sandcastle from the URL, named or a share link, we always default to the editor
    • If not loading a specific sandcastle we fall to the setting
    • The setting will default to Gallery for new users
    • This is meant as a convenience factor for more regular/power users
• Implements dialogs for sandcastle using stratakit variables for consistent style and uses this for the settings modal

I meant to also include the popovers for the sandcastle metadata and share interaction in this PR but opted to do them in a follow up to keep the PR more focused and easier to review.

Issue number and link

part of #12566

Testing plan

• Run sandcastle using npm run dev inside the package or npm run build-sandcastle and npm start from the project root
• Play with the new settings modal
• Make sure settings are preserved after refresh
• Make sure the editor font matches
• Make sure changing the theme from the sidebar and within the modal both work and don't conflict
• Make sure the default starting panel works as expected

Author checklist

• I have submitted a Contributor License Agreement
• I have added my name to CONTRIBUTORS.md
• I have updated CHANGES.md with a short summary of my change
• I have added or updated unit tests to ensure consistent code coverage
• I have updated the inline documentation, and included code examples where relevant
• I have performed a self-review of my code

[github-actions]

Thank you for the pull request, @jjspace!

✅ We can confirm we have a CLA on file for you.

[lukemckinstry]

Looks good 👍 Just one actionable comment but otherwise good to go.

[lukemckinstry]

Is text replacement from trying the write kiwi referring to the library. This should be changed, right?

[jjspace]

This is already correct since we're using the stratakit components. This overrides the position anytime the badge is used inside a field label.

[lukemckinstry]

ok thanks for explaining the backstory offline that the strata codebase uses emojis for class names

[lukemckinstry]

The modal looks good on mobile and responsive to page resizes. The main page (viewer and gallery/editor) do not seem optimized for smaller screens yet, is that coming in a future PR?

[jjspace]

Longer term we've discussed making sandcastle "look nice" on mobile even if it's not very functional. However this is not a focus for the first version.
These styles were based on the example from the AriaKit Dialog sample code which already included this so I just kept it. It's especially good because this is a very generic component so when we do take a pass for mobile styles this is already ready to go.

[lukemckinstry]

Sounds good re: the modal

I know it is outside the scope of this PR, but for general mobile support for the new sandcastle, I am in favor of some basic support to view at least code right off the bat, rather than following up later, if that is reasonable. I tried viewing in mobile using developer tools and it was not usable.

[lukemckinstry]

Approved 👍

Not going to merge per @jjspace's request since this is dependent on another pending branch