Spacer: refactor away from the createComponent function

[ciampo]

Description

Fixes partially #34290.

How has this been tested?

Technically there should be no behavioral changes.

The project should build, the tests should pass, the component should behave as before in Storybook and in the block editor.

Types of changes

Refactor

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.
• N/A 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).