⭐️ add support for using http proxies

[imilchev]

• Make sure the proxy is used by cnspec
• make sure the operator uses the proxy too when reporting status upstream

[czunker]

This PR solves #853

[czunker]

For testing, I used network policies to limit the traffic. I came across these messages for the image scan:

k -n mondoo-operator logs pod/k8s-containers-scan-now-dqd4m -f                                                                                           ✔ │ minikube ○ │ 14:07:05 
→ loaded configuration from /etc/opt/mondoo/mondoo.yml using source --config
→ load inventory inventory-file=/etc/opt/mondoo/inventory.yml
→ using service account credentials
→ discover related assets for 1 asset(s)
x failed to convert container image to asset error="could not resolve image quay.io/jetstack/cert-manager-cainjector@sha256:7c65d8478484155f6f1886b1ed60064e854c7c371b1fddbe220c71e5574e6526. Get \"https://quay.io/v2/\": dial tcp 34.228.154.221:443: i/o timeout"
x failed to convert container image to asset error="could not resolve image calico/cni@sha256:3be3c67ddba17004c292eafec98cc49368ac273b40b27c8a6621be4471d348d6. Get \"https://index.docker.io/v2/\": dial tcp 3.216.34.172:443: i/o timeout"
x failed to convert container image to asset error="could not resolve image calico/node@sha256:8e34517775f319917a0be516ed3a373dbfca650d1ee8e72158087c24356f47fb. Get \"https://index.docker.io/v2/\": dial tcp 44.205.64.79:443: i/o timeout"
x failed to convert container image to asset error="could not resolve image registry.k8s.io/etcd@sha256:51eae8381dcb1078289fa7b4f3df2630cdc18d09fb56f8e56b41c40e191d6c83. Get \"https://registry.k8s.io/v2/\": dial tcp 34.96.108.209:443: i/o timeout"
x failed to convert container image to asset error="could not resolve image registry.k8s.io/kube-controller-manager@sha256:6286e500782ad6d0b37a1b8be57fc73f597dc931dfc73ff18ce534059803b265. Get \"https://registry.k8s.io/v2/\": dial tcp 34.96.108.209:443: i/o timeout"
x failed to convert container image to asset error="could not resolve image registry.k8s.io/kube-proxy@sha256:4bcb707da9898d2625f5d4edc6d0c96519a24f16db914fc673aa8f97e41dbabf. Get \"https://registry.k8s.io/v2/\": dial tcp 34.96.108.209:443: i/o timeout"
x failed to convert container image to asset error="could not resolve image gcr.io/k8s-minikube/storage-provisioner@sha256:18eb69d1418e854ad5a19e399310e52808a8321e4c441c1dddad8977a0d7a944. Get \"https://gcr.io/v2/\": dial tcp 66.102.1.82:443: i/o timeout"

This client is not taking up the proxy. But I'm not sure whether this was intended by the request. The linked issue only mentions the API proxy.

[czunker]

For some scans, I see the requests in the proxy logs and also the assets in the console.

[czunker]

During a test, I had an error in my setup. But nice to see we get a meaningful error message:

error: failed to do request: Post "https://api.edge.mondoo.com/PolicyResolver/SynchronizeAssets": proxyconnect tcp: dial tcp 192.168.1.87:3128: connect: connection refused

[czunker]

Node scan is now also working via proxy:

Scanned 1 assets

Ubuntu 22.04.2 LTS
    D minikube

[czunker]

LGTM. Thanks @imilchev