Improve LFS client performance and fix compatibility with Azure DevOps

The LFS client that is used in repository mirroring had a few
shortcomings:

1. Chunked transfers were never used because the Content-Length was
always specified. We now only including Content-Length if chunked
encodings are not requested.

2. Azure DevOps passes in the username in the upload URL, but this cause
HTTParty to serialize this in the Authorization header instead of using
the mirror credentials. We now strip the URL of username/passwords if
HTTP Basic Auth is used.

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/340482

Changelog: fixed