[Feature] Add Support for HTTPS/TLS Proxy in tun2socks

[slavb18]

Description

Currently, tun2socks lacks support for routing traffic through an HTTPS/TLS proxy. Adding this feature would improve compatibility and broaden the range of supported network environments.

Problem:

When attempting to use an HTTPS proxy with tun2socks, users encounter the error in squid caching proxy:
error: transaction-end-before-headers

This suggests that the connection fails due to the lack of TLS support in the current proxy implementation.

Is this feature related to a specific bug?

No response

Do you have a specific solution in mind?

Implement HTTPS CONNECT method support in tun2socks to establish tunnels through HTTPS proxies.
Integrate TLS support using OpenSSL to handle encrypted proxy connections.

Provide configuration options for users to specify HTTPS proxy settings, including Custom CA certificates for verifying proxy identity

[xjasonlyu]

Yea, that sounds like a good feature to have.