fix: add --socks5 and --connect flags to send subcommand (#1053)

Allow users to specify SOCKS5 and HTTP proxy settings directly
on the send subcommand, enabling both syntaxes:
- croc --socks5 "..." send file.txt (existing global flag)
- croc send --socks5 "..." file.txt (new, more intuitive)

This fixes the issue where users expected the more natural syntax
of specifying flags after the subcommand, which previously only
worked via the SOCKS5_PROXY environment variable.

Fixes #1051

Co-authored-by: Murat Aslan <murataslan1@users.noreply.github.com>