[Feature] Life cycle hook in all commands

[unix]

Expected:

• add life cycle hooks
• include at least init
• support async function
• No breaking changes

Examples:

export class Command implements Init {
  async init(): void {}
}

Programme:

• Add Init abstract class
• Check the init hook at initialization and call it if it exists

Others:

• Is it possible to capture exit code to achieve exit? (like user exit: command + c or error)

[unix]

It looks over-design, marked as pending.