feat: Craft 3: Add craft\console\controllers\HelpController with --asJson flag

[khalwat]

Description

PR for Craft 3

This adds a craft\console\controllers\HelpController that adds a --asJson flag, to allow for external API integration, such as with Fig for CLI autocomplete.

Usage:

All commands:

php craft help --asJson

Individual commands:

php craft help <command/name> --asJson

Alternately, the -j flag can be used as an option alias

If the --asJson flag isn't set, it calls through to the parent yii\console\controllers\HelpController to do its normal thing.

Related issues

n/a

[brandonkelly]

Craft 3.7.56 and 4.2.6 are out with this! (via #12074)