Try alternate list item jump fix. (#12941)

* Try alternate list item jump fix.

This PR is an alternative to #12590, and also fixes #12526. Props @Naerriel for initial work and inspiration.

The different approach taken here is to embrace that we are applying a specific margin to our list items and overrides bleed from wp-admin. In doing so it moves these margins to the editor styles stylesheet, which is a more appropriate place for it.

* Move to "initial".

packages/editor/src/editor-styles.scss

@@ -14,6 +14,11 @@ ul,
 ol {
 	margin: 0;
 	padding: 0;
+
+	li {
+		// This overrides a bottom margin globally applied to list items in wp-admin.
+		margin-bottom: initial;
+	}
 }
 
 ul {