Add Support for Overloading Synced Patterms

[justlevine]

What problem does this address?

Developers should be able to overload a synced pattern with a custom React component.

The problem is that WPGraphQL Content Blocks currently flattens Pattern blocks. wpengine/wp-graphql-content-blocks#345

What is your proposed solution?

• Replace core/block with core/synced-pattern (Changes GraphQL response structure) wpengine/wp-graphql-content-blocks#347
• Backport fix to snapwp-helper
• Update fragments (if necessary) + block components
• Update docs on overloading WP behavior.

What alternatives have you considered?

No response

Additional Context

No response

[justlevine]

@joelabreo227 once I handle the upstream part (first checklist item), this should be ready for reassignment to someone else to finish the rest.