Resource Import Support for ClientVPN Resources

### Name of the resource

AWS::EC2::ClientVpnAuthorizationRule

### Resource name

_No response_

### Description

According to the 'Resources that support import and drift detection operations' documentation [1] the following ClientVPN related resources are not currently supported by the CloudFormation resource import feature;

AWS::EC2::ClientVpnAuthorizationRule
AWS::EC2::ClientVpnEndpoint
AWS::EC2::ClientVpnRoute
AWS::EC2::ClientVpnTargetNetworkAssociation

Could the CloudFormation service be enhanced to support resource import of these resources please.

[1] https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/resource-import-supported-resources.html

### Other Details

_No response_

Start with the AWS documentation on resources that support import and drift detection, linked in the issue. Review the four named ClientVPN resources—ClientVpnAuthorizationRule, ClientVpnEndpoint, ClientVpnRoute, and ClientVpnTargetNetworkAssociation—and confirm that CloudFormation resource import support is documented for each when the work is complete.

Written by the indexing model from the issue text.