Always switch to editor when it should

[jjspace]

Description

Fixes a bug when you have a specific sandcastle loaded and click the "Open code" button on that same sandcastle in the gallery

Issue number and link

Part of #12566

Testing plan

• Run sandcastle with npm run dev in the package or npm run build-sandcastle and npm start at the project root
• Open the gallery and click any sandcastle
• Once it's loaded click the "Open code" button for that same sandcastle
• it should switch to the code and reload the sandcastle

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]

I notice when I click the "open code" button for a sandcastle that is already open, it reloads the scene in the viewer. This seems unnecessary. Can we skip this?

I see toggling the "gallery" and "editor" buttons does not reload the scene in the viewer, which seems better.

[jjspace]

I notice when I click the "open code" button for a sandcastle that is already open, it reloads the scene in the viewer.

This was intentional to keep the behavior consistent. If you click the card for a gallery item it will load it even if it is already loaded. I meant this to be a way to "re-run" without switching to the code panel. I think this is good.
I left this behavior for the switch to code button too to make sure it's starting "fresh" when viewing the code but I realize it may be a bit too much. I've updated the code to avoid re-running when switching to code and it's already loaded.

(The "active" detection is a little messy now relying on the url. I plan to change this a bit later based on some other open PRs but not in this one to avoid conflicts)

[lukemckinstry]

Good to go once CI is passing