hint which modules are available

[yosefy]

may be we can add option to "show available modules" or something like this

because this message:

{
	"error": "Invalid configuration.",
	"detail": "The module to run \"php74\" is not found among the available application modules."
}

is not very helpful

[tippexs]

This is a great point! This can be combined with the about endpoint. We will consider this as an enhancement