* Security: Make proxy endpoints not leak sensitive HTTP headers
Fixes CVE-2022-31130
* remove support for v1 manifests
* Security: Fix do not forward login cookie in outgoing requests
Co-authored-by: Will Browne <will.browne@grafana.com>
Moves common request proxy utilities to proxyutil package with
support for removing X-Forwarded-Host, X-Forwarded-Port,
X-Forwarded-Proto headers, setting X-Forwarded-For header
and cleaning Cookie header.
Using the proxyutil package to prepare and clean request
headers before resource calls.
Closes#21512