Refactor project structure to organize APIs (#24)

* Refactor project structure "api"
* fix bug conversione delle valute fiat in stablecoin in BinanceWrapper
* Refactor: WrapperHandler for managing API wrappers with retry logic; update related modules and tests
* Refactor: Update ProductInfo and Price classes to include aggregation methods; remove standalone aggregation functions
* fix docs

src/app/api/news/duckduckgo.py

@@ -0,0 +1,34 @@
+import json
+from typing import Any
+from agno.tools.duckduckgo import DuckDuckGoTools
+from app.api.base.news import Article, NewsWrapper
+
+
+def extract_article(result: dict[str, Any]) -> Article:
+    article = Article()
+    article.source = result.get("source", "")
+    article.time = result.get("date", "")
+    article.title = result.get("title", "")
+    article.description = result.get("body", "")
+    return article
+
+class DuckDuckGoWrapper(NewsWrapper):
+    """
+    A wrapper for DuckDuckGo News search using the Tool from agno.tools.duckduckgo.
+    It can be rewritten to use direct API calls if needed in the future, but currently is easy to write and use.
+    """
+
+    def __init__(self):
+        self.tool = DuckDuckGoTools()
+        self.query = "crypto"
+
+    def get_top_headlines(self, limit: int = 100) -> list[Article]:
+        results = self.tool.duckduckgo_news(self.query, max_results=limit)
+        json_results = json.loads(results)
+        return [extract_article(result) for result in json_results]
+
+    def get_latest_news(self, query: str, limit: int = 100) -> list[Article]:
+        results = self.tool.duckduckgo_news(query or self.query, max_results=limit)
+        json_results = json.loads(results)
+        return [extract_article(result) for result in json_results]
+