Add rules

• Added rule always_declare_return_types - @riccardocucia
• Added rule avoid_unused_constructor_parameters - @riccardocucia
• Added rule prefer_final_fields - @riccardocucia
• Added rule prefer_final_locals - @riccardocucia
• Added rule sort_pub_dependencies - @riccardocucia
• Added rule type_annotate_public_apis - @riccardocucia
• Added rule unawaited_futures - @riccardocucia
• Added rule use_named_constants - @riccardocucia
• Added rule use_super_parameters - @riccardocucia