AWS::CodePipeline::Webhook - Secret Token as a non-string

## Add non-string options for AWS::CodePipeline::Webhook-WebhookAuthConfiguration-Secret Token

Quick Sample Summary:
1. Title -> AWS::CodePipeline::Webhook-WebhookAuthConfiguration-Secret Token

2. Scope of request -> New option for existing attribute:

AWS::CodePipeline::Webhook-WebhookAuthConfiguration-Secret Token supports string values, including `!Ref` to `noEcho` CloudFormation Parameters. It does not support reading the value from SSM, and Secrets Manager values need to be passed in via an in-line `resolve` rather than referencing an ARN or path.

3. Expected behavior -> Ideal behavior would be similar to environment variables within AWS::CodeBuild::Project:

```console
- Type: PARAMETER_STORE
Value: /path/to/ssm/secret/value
```
Values for `Type` should include `STRING`, `PARAMETER_STORE`, and `SECRETS_MANAGER` to begin.

4. Test case recommendation -> it should help me store an authorization token once within AWS and retrieve the current stored value at CloudFormation build time.

6. Category tag (optional) -> Dev Tools

Start with the AWS::CodePipeline::Webhook WebhookAuthConfiguration Secret Token entry and compare the requested Type values with the AWS::CodeBuild::Project environment-variable example in the issue. Done means the resource supports STRING, PARAMETER_STORE, and SECRETS_MANAGER sources and can retrieve the current stored authorization token at CloudFormation build time.

Written by the indexing model from the issue text.