Tests: Synchronize Theme.JSON unit test between Core and Gutenberg.

Merges the changes from Core and Gutenberg for the following tests:

- WP_REST_Global_Styles_Controller_Test
- Tests_Theme_wpThemeJsonResolver
- Tests_Theme_wpThemeJsonSchema
- Tests_Theme_wpThemeJson

This will help ensure the stability of the theme.json style generation.

Props ajlende, scruffian, aaronrobertshaw, get_dave, youknowriad.
Fixes #60387.

git-svn-id: https://develop.svn.wordpress.org/trunk@57662 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/data/themedir1/block-theme-child/styles/variation-a.json

@@ -0,0 +1,18 @@
+{
+	"version": 2,
+	"settings": {
+		"blocks": {
+			"core/paragraph": {
+				"color": {
+					"palette": [
+						{
+							"slug": "dark",
+							"name": "Dark",
+							"color": "#010101"
+						}
+					]
+				}
+			}
+		}
+	}
+}

tests/phpunit/data/themedir1/block-theme-child/theme.json

@@ -1,6 +1,6 @@
 {
 	"$schema": "https://schemas.wp.org/trunk/theme.json",
-	"version": 1,
+	"version": 2,
 	"settings": {
 		"color": {
 			"palette": [

tests/phpunit/data/themedir1/block-theme/styles/variation-a.json

@@ -0,0 +1,18 @@
+{
+	"version": 2,
+	"settings": {
+		"blocks": {
+			"core/paragraph": {
+				"color": {
+					"palette": [
+						{
+							"slug": "light",
+							"name": "Light",
+							"color": "#f2f2f2"
+						}
+					]
+				}
+			}
+		}
+	}
+}

tests/phpunit/data/themedir1/block-theme/theme.json

@@ -1,6 +1,6 @@
 {
 	"$schema": "https://schemas.wp.org/trunk/theme.json",
-	"version": 1,
+	"version": 2,
 	"title": "Block theme",
 	"settings": {
 		"color": {
@@ -42,11 +42,11 @@
 				}
 			],
 			"customFontSize": false,
-			"customLineHeight": true
+			"lineHeight": true
 		},
 		"spacing": {
-			"units": ["rem"],
-			"customPadding": true,
+			"units": [ "rem" ],
+			"padding": true,
 			"blockGap": true
 		},
 		"blocks": {
@@ -63,8 +63,8 @@
 			}
 		}
 	},
-	"styles" : {
-		"blocks" :{
+	"styles": {
+		"blocks": {
 			"core/post-featured-image": {
 				"shadow": "10px 10px 5px 0px rgba(0,0,0,0.66)",
 				"filter": {
@@ -122,7 +122,7 @@
 		{
 			"name": "custom-single-post-template",
 			"title": "Custom Single Post template",
-			"postTypes": ["post"]
+			"postTypes": [ "post" ]
 		}
 	],
 	"templateParts": [