Separator block: Add width options

[davipontesblog]

What

It would be nice to be able to change the width of the separator line with a UI, making it lighter, or heavier based on px or different units of measure.

Why

This would improve the block's usability when designing a page, for example.

How

No response

[Addison-Stavlo]

For feature requests for core blocks, we should try to open an issue in the home repo: www.github.com/wordpress/gutenberg - that way core community and design can weigh in if necessary, but also because it allows other open source contributors to more easily pick up this task. 😁