[FEATURE] serve: Add '--simple-index' parameter

The directory listing of the UI5 Server has been overhauled by
integrating parts of the serve-index[1] project (see [2]).

The '--simple-index' flag allows to toggle between a detailed- and a
simplified rendering of the directory index.

Thanks to @jkoenig134 for this contribution!

[1] https://github.com/expressjs/serve-index
[2] SAP/ui5-server#253

lib/cli/commands/serve.js

@@ -25,6 +25,11 @@ serve.builder = function(cli) {
 			default: false,
 			type: "boolean"
 		})
+		.option("simple-index", {
+			describe: "Use a simplified view for the server directory listing",
+			default: false,
+			type: "boolean"
+		})
 		.option("accept-remote-connections", {
 			describe: "Accept remote connections. By default the server only accepts connections from localhost",
 			default: false,
@@ -87,6 +92,7 @@ serve.handler = async function(argv) {
 		port,
 		changePortIfInUse,
 		h2: argv.h2,
+		simpleIndex: !!argv.simpleIndex,
 		acceptRemoteConnections: !!argv.acceptRemoteConnections,
 		cert: argv.h2 ? argv.cert : undefined,
 		key: argv.h2 ? argv.key : undefined,

test/lib/cli/commands/serve.js

@@ -14,7 +14,8 @@ const defaultInitialHandlerArgs = Object.freeze({
 	key: path.join(os.homedir(), ".ui5", "server", "server.key"),
 	loglevel: "info",
 	t8r: "npm",
-	translator: "npm"
+	translator: "npm",
+	simpleIndex: false
 });
 
 const projectTree = {
@@ -56,6 +57,7 @@ test.serial("ui5 serve: default", async (t) => {
 		changePortIfInUse: true,
 		acceptRemoteConnections: false,
 		h2: false,
+		simpleIndex: false,
 		port: 8080,
 		cert: undefined,
 		key: undefined,
@@ -92,6 +94,7 @@ test.serial("ui5 serve --h2", async (t) => {
 		changePortIfInUse: true,
 		acceptRemoteConnections: false,
 		h2: true,
+		simpleIndex: false,
 		port: 8443,
 		key: "randombyte-likes-ponies-key",
 		cert: "randombyte-likes-ponies-cert",
@@ -163,6 +166,7 @@ test.serial("ui5 serve --key --cert", async (t) => {
 		changePortIfInUse: true,
 		acceptRemoteConnections: false,
 		h2: true,
+		simpleIndex: false,
 		port: 8443,
 		key: "ponies-loaded-from-custompath-key",
 		cert: "ponies-loaded-from-custompath-crt",
@@ -207,6 +211,7 @@ test.serial("ui5 serve --sap-csp-policies", async (t) => {
 		changePortIfInUse: true,
 		acceptRemoteConnections: false,
 		h2: false,
+		simpleIndex: false,
 		port: 8080,
 		cert: undefined,
 		key: undefined,