Rewrite

[cnpryer]

Closes #128

• Temporarily yanks huak activate (see Use rexpect for activate command #486)
• huak add will add dependencies without version specifiers
• Adds cli arg pass-through (closes Can't pass args to underlying tools #467)
• Removes HUAK_MUTE_SUBCOMMAND (tests now use Verbosity::Quiet)
• Adds basic VirtualEnvironmentConfig
• Adds Terminal abstraction
• Improves Python discovery
• Ditches the command-per-module project layout
• More idiomatic Rust
• Improves Project and VirutalEnvironment abstractions
• Now uses OperationConfig for public ops functions
• Adds --quiet
• Exits with code from underlying process if non-zero