Feature request: Include/Exclude Interface for AWS Lambda Builders

### Describe your idea/feature/enhancement
There are currently two opposing feature requests that go hand-in-hand. One is to include files/directories in the resultant build package, and one is for exclusion. Both of these are genuine use-cases across various runtimes, and, as such, we believe should be handled together though a common include/exclude interface for the Lambda Builders library.

Include: Issue #430, PR #431
Exclude: Issue #185, PR #424

This should start with an initial design document, and once approved, can be implemented. The important notes for the design to address:
- What does the interface look like? e.g. is part of the JSON RPC, is it through a configuration file, etc?
- How to make the implementation general across runtimes. Are there any runtimes for which this feature should be ignored?