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.
Built from https://develop.svn.wordpress.org/trunk@53353


git-svn-id: http://core.svn.wordpress.org/trunk@52942 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-alpha-53352';
+$wp_version = '6.1-alpha-53353';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.