(cherry picked from commit f66f8ab)

This change attempts to provide a catch-all safety net for circumstances
where an index server is behaving badly when ranged requests are made.

Additionally, this change also helps guard against  missing
"Content-Range" headers in specific scenarios.

(cherry picked from commit b7bc5ce)

(cherry picked from commit 120f289)

…dling of range requests with negative offsets

see #9056 (comment)

(cherry picked from commit a70330b)

…t range requests but do not respect them

(cherry picked from commit fd8489e)

Resolves: #9039
(cherry picked from commit 7bf0ee7)

Because warehouse doesn't send a charset, this can get decoded as something
other than utf-8, which doesn't encode (as utf-8) back to the same bytes. For
hash purposes especially, just look at the original bytes.

(cherry picked from commit 28d5c00)

(cherry picked from commit 0266156)