add system status service and mock data

src/app/system-status.ts

@@ -0,0 +1,17 @@
+export interface SystemStatus {
+    alloc: number;
+    connectionServiceStatus: any;
+    cpuPercent: number; // allows returns 0
+    discoveryEnabled: boolean;
+    discoveryErrors: any;
+    discoveryMethods: number;
+    goroutines: number;
+    lastDialStatus: any;
+    myID: string;
+    pathSeparator: string;
+    startTime: string;
+    sys: number;
+    themes: string[];
+    tilde: string;
+    uptime: number;
+}