Revert "Restrict paramiko to old versions for now"

This reverts commit c86df77aa68dc5331b98df3fa038faee77c578ad.
Revert "Revert "Handle raw data I/O.""

This reverts commit 0c8a3e2334631f5fc20cb7933d0005353ea6a46e.
Revert "Revert "Clean up remote.py and misc.py changes.""

This reverts commit 02504c3fd27d788e2e446369015b14cbf259a8d2.
Use SFTPClienti get for long reads/writes

Modified remote.py to use the paramiko SFTPClient get
method to extract long files (mostly tar files) from
the remote host.  The code formerly saved the data
in a long local string which was very inefficient.

Fixes: 8261
Signed-off-by: Warren Usui <warren.usui@inktank.com>
FIx mktemp dir and redundant Paramiko connecting.

Use previously initialized connection for sftp_get calls.
Use local directory for tarball temp file location.
Fix linter errors

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Rewrite most file-retrieval functions

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>