New attributes for AWS::EC2::Subnet to support subnet CIDR IPAM automation

### Name of the resource

AWS::EC2::Subnet

### Resource name

_No response_

### Description

New attributes added to api call [CreateSubnet](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateSubnet.html) to support the new capability [Amazon VPC IP Address Manager now automates IP address assignments for VPC subnets](https://aws.amazon.com/about-aws/whats-new/2023/11/amazon-vpc-ip-address-manager-assignments-vpc-subnets/).
The new attributes are:
- `Ipv4IpamPoolId`
- `Ipv4NetmaskLength`
- `Ipv6IpamPoolId`
- `Ipv6NetmaskLength`

It is required to add those to the [AWS::EC2::Subnet](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-subnet.html) resource.

In addition, to fully support this scenario, it is also required to:
(See issue [1852](https://github.com/aws-cloudformation/cloudformation-coverage-roadmap/issues/1852))
1. add new attribute to resource [AWS::EC2::IPAMPool](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-ipampool.html) according to api call [CreateIpamPool](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateIpamPool.html).
2. add new resource according to data type [IpamPoolSourceResourceRequest](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_IpamPoolSourceResourceRequest.html)

### Other Details

_No response_

Start with the AWS::EC2::Subnet resource documentation and the CreateSubnet API reference named in the issue. Review the related AWS::EC2::IPAMPool work in issue 1852 to understand the broader scope. Done means the four listed IPAM attributes are supported for AWS::EC2::Subnet.

Written by the indexing model from the issue text.