HTTPFileSystem breaks when range requests are not supported

[dholth]

from fsspec.core import url_to_fs

ufs, url = url_to_fs("https://example.org/")
f = ufs.open("https://example.org/no-range-requests/data.txt")
f.seek(8192)
f.read(1)

Will raise # ValueError: The HTTP server doesn't appear to support range requests.

I was having trouble with cache options, but it turns out I was sending simplecache:: to the wrong place; this does work, but I don't really want to keep the seekable file around after the file is closed. Trying to be careful to open the file only once.

[martindurant]

Specifically:

• HTTPFile, which supports seeking, sends range requests and is refused by the server
• HTTPStreamFile does not use range, but does not support seek().
• HTTPStreamFile ought to support some caching modes, particularly "all" and "first", but is hard-coded to "none".

[dholth]

IIUC, for my use case I could

• use simplecache:: or filecache::
• enhance those so that the cache only keeps a file or two if I'm worried about disk space, like python TemporaryFile's delete-file-on-close
• Edit HTTPStreamFile so that it can fetch a range, if that range is right after whatever we've fetched so far, and use the file-level "all" cache instead of the filesystem wrappers simplecache::

[martindurant]

cf #1629