major changes:

- introduce flask cache
- use replaceAll together with encodeURI component on client
- many more

server/app/__init__.py

@@ -1,11 +1,22 @@
 from flask import Flask
 from flask_cors import CORS
 
+from flask_caching import Cache
+
+config = {
+    "CACHE_TYPE": "SimpleCache",
+    "CACHE_DEFAULT_TIMEOUT": 300
+}
+
+cache = Cache(config = config)
 
 def create_app():
     app = Flask(__name__)
     CORS(app)
 
+    app.config.from_mapping(config)
+    cache.init_app(app)
+
     from . import api
     app.register_blueprint(api.bp, url_prefix='/')