add ppn search

src/logic/webrequest.py

@@ -80,6 +80,12 @@ class WebRequest:
         response = requests.get(PPN_URL.format(searchterm), timeout=self.timeout)
         return response.text
 
+    @sleep_and_retry
+    @limits(calls=RATE_LIMIT, period=RATE_PERIOD)
+    def search_ppn(self, ppn: str) -> str:
+        response = requests.get(API_URL.format(ppn), timeout=self.timeout)
+        return response.text
+
     def get_book_links(self, searchterm: str) -> list[str]:
         response: str = self.search_book(searchterm)  # type:ignore
         soup = BeautifulSoup(response, "html.parser")