New Pattern: aws-msk-lambda

Lambda recently added support for MSK (Managed Streaming for Apache Kafka) as an event source (https://aws.amazon.com/about-aws/whats-new/2020/08/aws-lambda-now-supports-amazon-managed-streaming-for-apache-kafka-as-an-event-source/)

### Use Case
With this new integration, customers can build Apache Kafka consumer applications with Lambda functions without needing to worry about infrastructure management.

### Other
There's an open issue where the new property for Lambda (`Topics` - https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-lambda-eventsourcemapping.html#cfn-lambda-eventsourcemapping-topics) is not available in the CDK yet. Here's the GitHub issue I created on their repository: https://github.com/aws/aws-cdk/issues/10138

* [x] :wave: I may be able to implement this feature request

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This is a :rocket: Feature Request

Start by locating the existing AWS Solutions Constructs patterns for Lambda event sources and the CDK support discussed in issue aws-cdk#10138. Review the AWS CloudFormation EventSourceMapping documentation for the MSK integration and its Topics property. Done means the aws-msk-lambda pattern is implemented and covered by the repository's relevant tests.

Written by the indexing model from the issue text.