Fix query-no-results block from showing when their is one search result #47793

[petitphp]

This allows inner blocks to operate on the correct query when checking for the state of the loop.

What?

This is an attempt at addressing #47793
Store the post-template block's query in globals. In post-content and post-featured-image blocks, use the query if available instead of the global one.

⚠️ Warning : The current behavior was meant to fix an issue where some plugins would work properly because the check to in_the_loop would fail. This PR should be tested to see if it reintroduces the bug or not.

Why?

This change is to avoid manipulating the global wp_query in the post-content and post-featured-image blocks.

These blocks are typically used as inner blocks of the post-template block. When the post-template block is configured to use the global wp_query it'll create a clone of it instead of using it directly, so the two aforementioned blocks shouldn't operate on the global one.

How?

In post-template, the query is stored in a global. In the blocks post-content and post-featured-image this query is retrieved and used instead of using the functions for the global query.

Testing Instructions

1. Activate Twenty Twenty-Three, or insert the No Results block in a search template
2. Search for a keyword that should have 1 search result (e.g. "hello world")
3. The No Results block should not be show

[ocean90]

This now obsoleted by #49904 and #53772.