feat: เพิ่มระบบ caching

- เพิ่ม caching interceptor และ service

- เพิ่ม configสำหรับ caching

accounting-ng-nuttakit/src/app/services/caching.service.ts

@@ -0,0 +1,41 @@
+import { Injectable } from '@angular/core';
+import { HttpResponse } from '@angular/common/http';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class CachingService {
+  private cache = new Map<string, [Date, HttpResponse<any>]>();
+  private cacheDurationInMs = 600000; // 5 minutes
+
+  constructor() { }
+
+  get(key: string): HttpResponse<any> | null {
+    const tuple = this.cache.get(key);
+    if (!tuple) {
+      return null;
+    }
+
+    const expires = tuple[0];
+    const httpResponse = tuple[1];
+
+    // Don't observe expired keys
+    const now = new Date();
+    if (expires && expires.getTime() < now.getTime()) {
+      this.cache.delete(key);
+      return null;
+    }
+
+    return httpResponse;
+  }
+
+  put(key: string, value: HttpResponse<any>): void {
+    const expires = new Date();
+    expires.setMilliseconds(expires.getMilliseconds() + this.cacheDurationInMs);
+    this.cache.set(key, [expires, value]);
+  }
+
+  clear(): void {
+    this.cache.clear();
+  }
+}