Add version info support using clap

[lvillis]

Description

bpftop currently lacks a way to display its version. Running the binary always starts the TUI interface, and there’s no support for options like -V, -v, or --version.

Proposal

Integrate the clap library to add basic argument parsing, including a version flag. This would allow users to check the version without launching the TUI.

Why It's Needed

Adding a version flag improves usability and aligns with common CLI tool behavior.