Editor: Update build_comment_query_vars_from_block to handle unapproved comments

[darerodz]

The build_comment_query_vars_from_block function has been updated recently in Gutenberg (see ​https://github.com/WordPress/gutenberg/pull/40612), where we solved a problem with comment previews not being rendered.

Some PHP unit tests related to that function are failing there because that function is already defined in WordPress 6.0, so, in order to make those tests work, we have to backport first the changes in that function into WordPress, as explained in ​https://github.com/WordPress/gutenberg/pull/40612#issuecomment-1110107499.

Backports some changes in build_comment_query_vars_from_block to handle comment previews done in the Gutenberg repo. We need these changes in core before merging ​https://github.com/WordPress/gutenberg/pull/40612 as explained in ​https://github.com/WordPress/gutenberg/pull/40612#issuecomment-1110107499.

Trac ticket: https://core.trac.wordpress.org/ticket/55634

@peterwilsoncc Would you mind committing this to Core? 🙏

(It's a prerequisite for ​https://github.com/WordPress/gutenberg/pull/40612 and ​https://github.com/WordPress/gutenberg/pull/40659, which will fix ​https://github.com/WordPress/gutenberg/issues/40601.)

[peterwilsoncc]

Also marking this as a bug as it's a long term feature WP that is needed for FSE too.

[peterwilsoncc]

In 53298:

Editor: Show comment previews in the Comment Query Loop.

Update build_comment_query_vars_from_block() to show previews of unmoderated comments to the original author of the comment. This duplicates the existing logic in wp_list_comments().

Props darerodz, bernhard-reiter, czapla.
Fixes #55634.

merged in https://core.trac.wordpress.org/changeset/53298

[hellofromTonya]

In 53353:

Editor: Add unit test for Comment Template block.

Backport of 2 tests from Gutenberg for the Comment Template block:

• test line and paragraph breaks are converted into HTML tags.
• test rendering of unapproved comment preview.

Follow-up to [53298], [53172], [53138].

Props bernhard-reiter, darerodz, gziolo, peterwilsoncc, hellofromTonya.
Fixes #55643.
See #55634.