Refactor URLInput component

[talldan]

Fixes #19056 in a round-about way.

Description

URLInput has for a while been a difficult component to work with, it's quite opinionated, and has some pretty complicated business-logic mixed with ui-logic. My feeling with this component, and the new LinkControl is that it might be cleaner to move towards a set of presentational components that aren't coupled to any WordPress specific code, and could live in @wordpress/components.

This PR attempts to decouple the component into BaseURLInput a presentational component that has no wordpress-specific logic. I could imagine this component in the future having minimal styles for an input and being less opinionated so that things like autoFocus and isRequired aren't hardcoded.

The BaseURLInput is configurable with different suggestion lists. It's used to build a URLInputWithInlineSuggestionList component (which implements the LinkControl style suggestion list) and URLInputWithPopoverSuggestionList (which implements the old popover style suggestion list, which may be something to get rid of in the future when it's no longer used).

The PR is still a bit buggy and needs further work, I had to move a lot of business logic around so there are still a few things to tidy up.

How has this been tested?

Just manual testing so far.

Types of changes

Refactor

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• 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. .