Top-level patterns

[richtabor]

What problem does this address?

Some patterns, like headers, footers and fullscreen hero areas are not meant to be placed within a parent block.

It's easy to forget to add a blank paragraph block, or hit "Insert after" before adding another pattern — which can lead to unintended placement of these patterns that meant to be placed at the top-level of a page.

What is your proposed solution?

What I'd like to reduce is the instances where you have to undo adding a pattern, find a better insertion point, find your pattern again, and add it again. Perhaps this could be achieved by adding a method to indicate a pattern should be added top-level from the pattern registration.

Screenshot

Here's what an incorrectly placed top-level pattern may look like: (A header added within a column)

[mtias]

This is extremely related to #39281