Split jslib into multiple modules (#363)

* Split jslib into multiple modules

common/src/services/state.service.ts

@@ -0,0 +1,27 @@
+import { StateService as StateServiceAbstraction } from '../abstractions/state.service';
+
+export class StateService implements StateServiceAbstraction {
+    private state: any = {};
+
+    get<T>(key: string): Promise<T> {
+        if (this.state.hasOwnProperty(key)) {
+            return Promise.resolve(this.state[key]);
+        }
+        return Promise.resolve(null);
+    }
+
+    save(key: string, obj: any): Promise<any> {
+        this.state[key] = obj;
+        return Promise.resolve();
+    }
+
+    remove(key: string): Promise<any> {
+        delete this.state[key];
+        return Promise.resolve();
+    }
+
+    purge(): Promise<any> {
+        this.state = {};
+        return Promise.resolve();
+    }
+}