feat(project): enhance select with clipboard, tmux, cd functionality

[zkhvan]

Description

Enhance z project select to support multiple actions, leveraging keybinds:

• enter: cd (or switch tmux session) to the project
• ctrl-y: yank the absolute path of the project
• alt-enter: if a GitHub remote exists, open it in the browser

A project now contains a "source", to indicate how the project was discovered. If a project is a "remote" project, navigating to the project will automatically clone the project.

The old z tmux psession use command has been removed in favor of z project select --tmux.