Use more specific summary text description for GetRemoteJsonKey

[homebysix]

This will distinguish the summary text from other summaries such as URLDownloader's.

Output before the change:

The following new items were downloaded:
    Downloaded Json                                                                    
    ---------------                                                                    
    https://www.cursor.com/api/download?platform=darwin-universal&releaseTrack=stable  

After the change:

JSON keys were extracted from the following URLs:
    Downloaded Json                                                                    
    ---------------                                                                    
    https://www.cursor.com/api/download?platform=darwin-universal&releaseTrack=stable