Editor: add text orientation for blocks with typography support.

Adds a new text orientation option to the typography block support, implemented with CSS writing-mode.

Props poena.
Fixes #59306.


git-svn-id: https://develop.svn.wordpress.org/trunk@56605 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/theme.json

@@ -263,7 +263,8 @@
 			"letterSpacing": true,
 			"lineHeight": false,
 			"textDecoration": true,
-			"textTransform": true
+			"textTransform": true,
+			"writingMode": false
 		},
 		"blocks": {
 			"core/button": {