Move the CLI to a framework like Cobra

[rdimitrov]

The following issue is about moving the CLI to a proper framework like cobra which would give us a few things for granted

Benefits:

• Automatic help generation and version handling
• Built-in shell completion support (bash/zsh/fish/PowerShell)
• Better flag validation and error messages
• Easier to add new commands/subcommands
• Consistent with popular CLI tools (kubectl, gh, hugo, etc.)
• More testable command structure

[deerajkumar18]

Hi @rdimitrov , I'd like to work on this enhancement . Pls assign this issue to me .

[rdimitrov]

Thanks, @deerajkumar18! I assigned it to you 👍

[deerajkumar18]

Hi @rdimitrov , have resolved the conflicts on the PR #1018 . Would like to get it reviewed .