Add `ssh` module

[plajjan]

Focus on SSH client!

• [ ] zig build
  • [ ] libssh
  • [ ] zlib
  • [ ] some crypto libs, like libcrypto or libgcrypt? or mbedtls?
  • [ ] nacl? or is this XOR with one of the above?
• [ ] design actor-centric interface for client
  • draw inspiration from existing TCP / TLS actors in Acton
  • see https://github.com/actonlang/acton/blob/main/base/src/net.act for "internal" Acton side of it
  • see https://github.com/actonlang/acton/blob/main/base/src/net.ext.c for C part of the plumbing

[precla]

Focus on SSH client!

• [ ] zig build

  • [x] libssh -> https://github.com/actonlang/libssh/pull/1
  • [x] zlib -> https://github.com/actonlang/zlib/tree/zig-kll
  • [x] some crypto libs, like libcrypto or libgcrypt? or mbedtls? -> libssh depends on either one of: libcrypto (openssl), gcrypt, mbedtls. -> use acton mbedtls https://github.com/actonlang/mbedtls/blob/zig-build-v0.13/build.zig
  • [ ] nacl? or is this XOR with one of the above?

• [ ] design actor-centric interface for client

  • draw inspiration from existing TCP / TLS actors in Acton
  • see https://github.com/actonlang/acton/blob/main/base/src/net.act for "internal" Acton side of it
  • see https://github.com/actonlang/acton/blob/main/base/src/net.ext.c for C part of the plumbing