added new electron tests supporting date mocking (#2947)

first PR for #2942 

- added new electron tests for calendar which test new css classes from
https://github.com/MichMich/MagicMirror/pull/2939
- moved some compliments tests from `e2e` to `electron` because of date
mocking
- removed mock stuff from compliments module

tests/electron/helpers/global-setup.js

@@ -0,0 +1,43 @@
+// see https://playwright.dev/docs/api/class-electronapplication
+// https://github.com/microsoft/playwright/issues/6347#issuecomment-1085850728
+// https://www.anycodings.com/1questions/958135/can-i-set-the-date-for-playwright-browser
+const { _electron: electron } = require("playwright");
+
+exports.startApplication = async (configFilename, systemDate = null, electronParams = ["js/electron.js"]) => {
+	global.electronApp = null;
+	global.page = null;
+	process.env.MM_CONFIG_FILE = configFilename;
+	process.env.TZ = "GMT";
+	jest.retryTimes(3);
+	global.electronApp = await electron.launch({ args: electronParams });
+	expect(global.electronApp);
+
+	if ((await global.electronApp.windows().length) === 1) {
+		global.page = await global.electronApp.firstWindow();
+		if (systemDate) {
+			await global.page.evaluate((systemDate) => {
+				Date.now = () => {
+					return new Date(systemDate);
+				};
+			}, systemDate);
+		}
+		expect(await global.page.title()).toBe("MagicMirror²");
+		expect(await global.page.isVisible("body")).toBe(true);
+	}
+};
+
+exports.stopApplication = async () => {
+	if (global.electronApp) {
+		await global.electronApp.close();
+	}
+	global.electronApp = null;
+	global.page = null;
+};
+
+exports.getElement = async (selector) => {
+	expect(global.page);
+	let elem = global.page.locator(selector);
+	await elem.waitFor();
+	expect(elem).not.toBe(null);
+	return elem;
+};