Support insecure registries with untrusted HTTPS certificates

[baronfel]

          @baronfel when configuring a registry as insecure, both podman and docker allow the connection to be either unencrypted HTTP or HTTPS with an untrusted certificate.

The implementation added in dotnet/sdk#39840 is only supporting the first.

Originally posted by @tmds in #571 (comment)

Our existing implementation should look at the configurations for both tools and configure the HttpClient instances to support the specific endpoints with untrusted certs.

[baronfel]

Closing as linked PR is implemented