Expose the Location header from Stream TUS initialization #20

Problem

cf stream create can initialize a resumable TUS upload, but the successful response provides the upload URL in the Location header. The shared request path currently discards successful response headers, so the command does not expose the URL required to continue the upload.

Expected behavior

Include the TUS upload URL in normal and structured command output.

Acceptance criteria

• A successful initialization exposes the Location value.
• Structured output includes a stable field for the upload URL.
• Other commands do not begin leaking unrelated response headers.
• Tests cover header casing and a missing Location header.