IRSA-6468: Support for Packager Script of URLs (Euclid, SphereX, Rubin, etc.)

[kpuriIpac]

Ticket: IRSA-6468

• Added support for a packager that downloads either a script (curl or wget) that the user can run, containing a list of urls of the products available in the datalink, or just a plain list of urls (in a txt file format)
• this is generalized, but the client may also provide a list of specific products to download. If available, only those will be downloaded. So this should work for Rubin as well.
• ToDo: Adding support for cutout service descriptor urls (and in general any data that has a service descriptor but not access_urls directly).
• Modified DownloadScript.java a little to support better filename generation from the given URL

Testing:
Euclid: https://irsa-6468-packager-script.irsakudev.ipac.caltech.edu/applications/euclid

• do an Image search (previously Explore Regions)
  • select any number of rows, and click on Prepare Download
  • test downloading all 3 script types (curl, wget, and plain urls)
  • try and choose different data products, including 'All data'