[QA] Ease maintenance of conan-completion script

Commands, subcommands and its options are Hard-coded for a specific version of conan.

To ease the maintenance, this informations could be generated based on conan help output (or by another way)

A good first step will be to fill automatically, the folowing variables for each commands :

        boolean_options=""
	arg_options=""
	map_options=""
	non_arg_options="recipe_path"