Support for the "New repository format for faster and smaller updates"

[pitsi]

A couple of days ago, fdroid announced this new feature for its repos
https://f-droid.org/en/2023/03/01/new-repo-format-faster-smaller-updates.html

I think it would be cool if fdroidcl supported it, because this is what happens now

$ fdroidcl update
https://f-droid.org/repo/index-v1.jar 100% |███████████████████████████████████████████████| (8.1/8.1 MB, 1.197 MB/s) [6s:0s]
https://fdroid.bromite.org/fdroid/repo/index-v1.jar 100% |██████████████████████████████████| (14/14 kB, 63.145 MB/s)

next time the update is ran (this one was run ~30 minutes later after the one above).

$ fdroidcl update
https://f-droid.org/repo/index-v1.jar  76% |████████████████████████████████           | (6.2/8.1 MB, 129.052 kB/s) [51s:15s]