Add standard block class to List blocks on frontend

[ndiego]

What problem does this address?

Currently, List blocks are rendered on the frontend as simply a <ul> or <ol> and do not include the standard block class wp-block-list. In the editor, this class is included.

Since other blocks use list markup, such as the Navigation block and Social Icons block, it can be hard for theme developers to target List blocks with custom CSS without inadvertantly targeting the list markup in other blocks.

What is your proposed solution?

I propose we update the List block to include the class wp-block-list. The frontend markup would then be <ul class="wp-block-list"> or <ol class="wp-block-list">.

[aristath]

Closing as a duplicate of #12420
PR already exists in #36676 👍

[ndiego]

Oops my apologies for the second Issue, thanks @aristath!