Add a CLI wrapper for TACIT

[Linyxus]

This PR adds a CLI wrapper tacit.

tacit is a small wrapper command for managing TACIT locally. Use tacit setup once to install the command and fetch the latest release, tacit update to update the cached JARs to the latest, and tacit serve to launch the MCP server.

Try it with:

curl -fsSL https://raw.githubusercontent.com/lampepfl/TACIT/refs/heads/tacit-cli/tacit -o tacit
chmod +x tacit
./tacit setup
tacit