Support HTTP proxy env variables

[pavolloffay]

Support HTTP proxy variables (some docs https://superuser.com/questions/944958/are-http-proxy-https-proxy-and-no-proxy-environment-variables-standard).

The codebase already supports it, but some places were missed. There were also two problems:

1. query grpc gateway was connecting to :16686 which is not recognized by NO_PROXY
2. grpc reporter in agent when used with all-in-one was connecting to :14250 also not recognized by NO_PROXY

Example of proxy vars set on OpenShift

 - name: HTTP_PROXY
              value: >-
                http://proxy-user1:foo@ec2-32-138-32-212.us-east-2.compute.amazonaws.com:3128
            - name: http_proxy
              value: >-
                http://proxy-user1:foo@ec2-32-138-32-212.us-east-2.compute.amazonaws.com:3128
            - name: HTTPS_PROXY
              value: >-
                http://proxy-user1:foo@ec2-32-138-32-221.us-east-2.compute.amazonaws.com:3128
            - name: https_proxy
              value: >-
                http://proxy-user1:foo@ec2-32-138-32-212.us-east-2.compute.amazonaws.com:3128
            - name: NO_PROXY
              value: >-
                .cluster.local,.svc,.us-east-2.compute.internal,10.0.0.0/16,10.128.0.0/14,127.0.0.1,169.254.169.254,172.30.0.0/16,api-int.rererer.qe.devcluster.openshift.com,localhost,test.no-proxy.com
            - name: no_proxy
              value: >-
                .cluster.local,.svc,.us-east-2.compute.internal,10.0.0.0/16,10.128.0.0/14,127.0.0.1,169.254.169.254,172.30.0.0/16,api-int.rerererer.qe.devcluster.openshift.com,localhost,test.no-proxy.com

PR is related to jaegertracing/jaeger-operator#2330

make build-binaries-linux
DOCKER_NAMESPACE=pavolloffay DOCKER_TAG=proxy-3 make docker-images-jaeger-backend

[codecov]

Codecov Report

Patch coverage is 100.00% of modified lines.

Files Changed	Coverage
cmd/agent/app/reporter/grpc/builder.go	100.00%
cmd/query/app/apiv3/grpc_gateway.go	100.00%
pkg/netutils/port.go	100.00%

📢 Thoughts on this report? Let us know!.

[yurishkuro]

lgtm

[pavolloffay]

@yurishkuro could you please re-review?