chore: add wdio tests for RTL mode (SAP#959)

FIXES: SAP#957

Author: ilhan007

packages/main/test/pages/Button.html

@@ -11,7 +11,6 @@
 
 	<script data-ui5-config type="application/json">
 		{
-			"rtl": false,
 			"compactSize": false
 		}
 	</script>

packages/main/test/specs/RTL.spec.js

@@ -0,0 +1,24 @@
+const assert = require("chai").assert;
+
+describe("RTL", () => {
+	it("language forces RTL, if RTL not specified", () => {
+		browser.url("http://localhost:8080/test-resources/pages/Button.html?sap-ui-language=he");
+
+		const buttonRoot = browser.$("#button1").shadow$(".ui5-button-root");
+		assert.strictEqual(buttonRoot.getProperty("dir"), "rtl", "dir is correctly set");
+	});
+
+	it("config forces RTL", () => {
+		browser.url("http://localhost:8080/test-resources/pages/Button.html?sap-ui-rtl=true");
+
+		const buttonRoot = browser.$("#button1").shadow$(".ui5-button-root");
+		assert.strictEqual(buttonRoot.getProperty("dir"), "rtl", "dir is correctly set");
+	});
+
+	it("config unsets RTL, although rtl language is used", () => {
+		browser.url("http://localhost:8080/test-resources/pages/Button.html?sap-ui-rtl=false&sap-ui-language=he");
+
+		const buttonRoot = browser.$("#button1").shadow$(".ui5-button-root");
+		assert.notOk(buttonRoot.getProperty("dir"), "dir is not present");
+	});
+});