Show `--help` option text when users doesn't provide any arguments

[FranjoMindek]

Currently we use commander-js for CLI.

We want:

1. For mode argument to be required and for that to be reflected in types
2. When user uses run-wasp-app without args, to send the --help option text

Currently that is impossible to do in an ergonomic way in commander-js.

With commander-js we can:

• Break 1) and make the mode optional, and then handle the undefined state ourslves
• Tap into configureOutput and outputError inside of it, and then for that specific error message override it with --help option text
• Disable it's exit handling logic completely and do it ourselves, almost same as above but worse

Because of that we decided to leave its default behavior, which prints error: missing required argument 'mode'