Prometheus: Templating queries should pass on custom headers (#50344)
Prometheus: Templating queries should pass on custom headers (#50344)

* pass on all headers except for accept headers

* touch up and testing

* add custom header values to resource queries

* remove my picture. oops

* handle gzip responses as well

* fix linting issues

* add my space

* no lint

* removed cookies from being proxied

* clean up and handle errors from io.reader.Close() calls
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