Add support for http proxy

[Mzack9999]

Please describe your feature request:

It would be helpful to add support for HTTP(s) proxy.

Describe the use case of this feature:

Proxies or reverse proxies exploitation as non-RFC compliant requests would be dropped.

The feasibility of the task should be investigated, as the unsafe nature of the requests makes it difficult to respect standard proxy communication protocols.

[Mzack9999]

The implementation should happen by replacing rawhttp with a fork of net/http and all the validation implicit rules disabled.

This will be indirectly implemented with #23 and #22