Twenty Twenty: Correct the border style of the pull quote block in the editor.

This change makes the border of the pull quote block visible in the editor when the user selects a border color or thickness,
by setting the default border style to solid.

Props nidhidhandhukiya, ugyensupport, dhruvang21, sabernhardt, divyeshk71, poena.
Fixes #62301.

git-svn-id: https://develop.svn.wordpress.org/trunk@59390 602fd350-edb4-49c9-b593-d223f7449a82

Author: carolinan

src/wp-content/themes/twentytwenty/assets/css/editor-style-block-rtl.css

@@ -791,7 +791,7 @@ hr.wp-block-separator.is-style-dots::before {
 /* Block: Pullquote -------------------------- */
 
 .editor-styles-wrapper .wp-block-pullquote {
-	border: none;
+	border: 0 solid;
 	color: inherit;
 	padding: 0;
 	position: relative;

src/wp-content/themes/twentytwenty/assets/css/editor-style-block.css

@@ -795,7 +795,7 @@ hr.wp-block-separator.is-style-dots::before {
 /* Block: Pullquote -------------------------- */
 
 .editor-styles-wrapper .wp-block-pullquote {
-	border: none;
+	border: 0 solid;
 	color: inherit;
 	padding: 0;
 	position: relative;