Add basic example to site logo block

[fabiankaegy]

Description

Add a basic example to the core/site-logo block.

Part of #30029

How has this been tested?

Locally using the bundles wp-env environment

Screenshots

While no Logo has been defined it shows the same Placeholder as the editor when you insert the block:

Once a Logo has been defined it uses that Logo from there on:

Types of changes

New feature: Add an example to the site logo block to add a live preview in the inserter

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).

[scruffian]

Thanks for this.

[jasmussen]

Thanks for your work here, and in #35590. One thing to consider when creating previews, is to make the preview itself as useful as possible, considering the purpose of the preview is to showcase the block itself. In the case of the site title, it's good for the viewport to be wide so we ideally avoid the text wrapping onto two lines.

In this case, I wonder if the site logo would have appeared bigger if the viewport width defined had been smaller than 500px?