Custom Domains - Support for HostedZoneName instead of HostedZoneId

[mbarneyjr]

Support using HostedZoneName instead of HostedZoneId in the Domain section of an AWS::Serverless::Api, like this:

Globals:
  Api:
    Domain:
      DomainName: www.domain.com
      CertificateArn: arn:aws:acm:us-east-1:000000000000:certificate/abcxyz
      EndpointConfiguration: REGIONAL
      Route53:
        HostedZoneName: www.domain.com
        DistributionDomainName: www.domain.com

This property would just need to be passed directly to the HostedZoneName property of the AWS::Route53::RecordSet created resource, since CloudFormation itself handles looking up the hosted zone ID.

When you create a stack using an AWS::Route53::RecordSet that specifies HostedZoneName, AWS CloudFormation attempts to find a hosted zone whose name matches the HostedZoneName. If AWS CloudFormation cannot find a hosted zone with a matching domain name, or if there is more than one hosted zone with the specified domain name, AWS CloudFormation will not create the stack.

[praneetap]

@mbarneyjr this sounds great! We can make HostedZoneId not required and always use the domain name.
If you are interested in contributing, the change would go here

[mbarneyjr]

Submitted a PR #1408