While implementing the resource pack downloader in another branch, I
noticed that most of the code in the success callback was identical in
both cases, safe for a few minute differences in strings. So, this tries
to make it easier to share this piece of code.
However, it still leaves the possibility of extending the methods in
ResourceModel to accomodate for cases where this similarity may not
hold.
Signed-off-by: flow <flowlnlnln@gmail.com>