Enable access of Tor socks proxy if required

[kushaldas]

To access onion services, this sdk needs to make the network calls over Tor. We can do it either by running the whole system's network over Tor (like in Tails, or in Qubes using whonix network vm), or it can access a local Tor socks proxy.

We should provide programming interface to allow the local Tor socks proxy.

[eloquence]

Just noting that this could be useful for accessing the dev env via hidden service (https://github.com/freedomofpress/securedrop/issues/5189).