Refactor formatTime into util class (#3073)

While looking at https://github.com/MichMich/MagicMirror/pull/3070 I
noticed that the weather and clock module do some formatTime stuff, so
why not use a common function for that?

---------

Co-authored-by: veeck <michael@veeck.de>

modules/default/utils.js

@@ -141,7 +141,37 @@ const getHeadersFromResponse = (expectedResponseHeaders, response) => {
 	return responseHeaders;
 };
 
+/**
+ * Format the time according to the config
+ *
+ * @param {object} config The config of the module
+ * @param {object} time time to format
+ * @returns {string} The formatted time string
+ */
+const formatTime = (config, time) => {
+	let date = moment(time);
+
+	if (config.timezone) {
+		date = moment.tz(config.timezone);
+	}
+
+	if (config.timeFormat !== 24) {
+		if (config.showPeriod) {
+			if (config.showPeriodUpper) {
+				return date.format("h:mm A");
+			} else {
+				return date.format("h:mm a");
+			}
+		} else {
+			return date.format("h:mm");
+		}
+	}
+
+	return date.format("HH:mm");
+};
+
 if (typeof module !== "undefined")
 	module.exports = {
-		performWebRequest
+		performWebRequest,
+		formatTime
 	};