Tagging in the `fargate-v2` component leads to failure if no `AWS::ElasticLoadBalancingV2::TargetGroup` is used

[petlitskiy]

The tagging in your current fargate-v2 component works like next:

1. first appearance:
   Name: help-site (from fargate-v2, assigned to AWS::ECS::Service)
2. second appearance:
   {Fn::Sub: "Name", Fn::Sub: "help-site"} (from ecs-task, assigned to AWS::ECS::TaskDefinition, but there is already defined { Key: "Name", Value: external_parameters[:component_name] })

All these lead to failure (duplicated tags):

  Task:
    Type: AWS::ECS::TaskDefinition
    Properties:
    ...
      Tags:
      - Key: Name
        Value: helpsiteTask
      - Key: Environment
        Value:
          Ref: EnvironmentName
      - Key: EnvironmentType
        Value:
          Ref: EnvironmentType
      - Key:
          Fn::Sub: Name
        Value:
          Fn::Sub: help-site

  EcsFargateService:
    Type: AWS::ECS::Service
    Properties:
      LaunchType: FARGATE
      Tags:
      - Key: Environment
        Value:
          Ref: EnvironmentName
      - Key: EnvironmentType
        Value:
          Ref: EnvironmentType
      - Key:
          Fn::Sub: Name
        Value:
          Fn::Sub: help-site

We can remove the tag to avoid tag duplication in AWS::ECS::TaskDefinition, but in this case the AWS::ECS::Service loses the Name tag:

  EcsFargateService:
    Type: AWS::ECS::Service
    Properties:
      LaunchType: FARGATE
      Tags:
      - Key: Environment
        Value:
          Ref: EnvironmentName
      - Key: EnvironmentType
        Value:
          Ref: EnvironmentType

And we cannot use the @aws-sdk/client-resource-groups-tagging-api to find out the needed ECS task by tag Name in this case (when no needs on targetGroup).

[petlitskiy]

In the case of when no targetGroup is used, this PR allows setting the custom Name tag (inherited from fargate-v2 template) for the ECS service.