Replace openssl with rustls

[yonas]

Problem to solve

rustls improves portability and removes the external dependency on openssl.

Proposal

Replace openssl usage with rustls.

Tasks to complete

• Replace openssl usage with rustls

[jcamiel]

Hi @yonas

OpenSSL is a dependency of cargo-rust, the Rust binding of libcurl. cargo-rust does offer a flag to use Rustls, but it is said in the docs:

Note that Rustls support is experimental within Curl itself and may have significant bugs, so we don't offer any sort of stability guarantee with this feature.

So for the moment, there is no strong need for Hurl to switch to Rustls.

[yonas]

@jcamiel Ok, instead of a complete switch over, can you provide the option to use rustls instead of openssl via a new feature?