Updated return parameter of YouTubeSearchTool (#10743)

**Description:** 
changed return parameter of YouTubeSearchTool
 

1. changed the returning links of youtube videos by adding prefix
"https://www.youtube.com", now this will return the exact links to the
videos
2. updated the returning type from 'string' to 'list', which will be
more suited for further processings

 **Issue:** 
Fixes #10742

 **Dependencies:** 
None


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---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>

libs/langchain/langchain/tools/youtube/search.py

@@ -32,7 +32,9 @@ class YouTubeSearchTool(BaseTool):
 
         results = YoutubeSearch(person, num_results).to_json()
         data = json.loads(results)
-        url_suffix_list = [video["url_suffix"] for video in data["videos"]]
+        url_suffix_list = [
+            "https://www.youtube.com" + video["url_suffix"] for video in data["videos"]
+        ]
         return str(url_suffix_list)
 
     def _run(