Add module.yaml validation

[yalosev]

Have to validate module.yaml file
Developers ofter forget name or writing something weird to the stage

[juev]

@yalosev

deckhouse-controller contains the following description of the module.yaml file:

type Definition struct {
	Name         string                       `yaml:"name"`
	Weight       uint32                       `yaml:"weight,omitempty"`
	Tags         []string                     `yaml:"tags"`
	Stage        string                       `yaml:"stage"`
	Description  string                       `yaml:"description"`
	Requirements *v1alpha1.ModuleRequirements `yaml:"requirements,omitempty"`

	DisableOptions DisableOptions `yaml:"disable"`
}

What exactly do we need to check in the file? And what are considered critical errors?