(pipes-sources): Add MSK stream source for EventBridge pipes

### Describe the feature

Add a implementation for the MSK stream source for EventBridge pipes in the `pipes-sources` module.

### Use Case

For feature completeness of the L2 pipes module this source is required.

### Proposed Solution

_No response_

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CDK version used

-

### Environment details (OS name and version, etc.)

-

Start by reviewing the existing implementations in the `pipes-sources` module and how the module models other EventBridge Pipes sources. Determine the required MSK source configuration and its integration points, then add the source with coverage consistent with the existing implementations; done means MSK is supported as an EventBridge Pipes stream source.

Written by the indexing model from the issue text.