Add route for handling Conan package uploads
This adds a route for utilizing Workhorse object storage acceleration with Conan package uploads. It is meant to mirror the behavior of the Maven route located directly above it, but with the specific endpoint for Conan uploads.
Conan upload issue: https://gitlab.com/gitlab-org/gitlab-ee/issues/13345
Main Conan issue: https://gitlab.com/gitlab-org/gitlab-ee/issues/8248