What

Use the fresh module types in tezt-cloud library to put the agent configuration there.

Why

Soonish, tezt-cloud will have its own configuration that we should distinguish from the agent configuration. This MR aims at solving that.

How

This add a new layer and cleans-up a bit the module env interface.

The idea is to have now the following abstraction layer:

Module Types is at the bottom and declares the types used by the library
The module Types also declares default values that can be used by the module Cli
Module on top of Cli such as Agent leverages Cli and Types to implement smart-constructor (in the future, those smart-constructors will also rely on the configuration of tezt-cloud)