Modify it to raise an exception when an invalid YAML is specified.

[yamagh]

Acceptance Criteria

• Specifying non existence module, an exception will be thrown.
• Specifying non existence entity, an exception will be thrown.
• Specifying non existence attribute, an exception will be thrown.
• Specifying single-tenant entity, an exception will be thrown.

Task

• Create validate action in public scope.
• Fixture_Setup action use the validate action.