DynamoDB stream support

[blazejkustra]

Summary:

This PR aims to support DynamoDB streams in dynamode, so that it's much easier to work with them.

Code sample:

import type { Context, DynamoDBStreamEvent } from 'aws-lambda';
import Stream from 'dynamode/stream';

async function itemStream(event: DynamoDBStreamEvent, context: Context): void {
  const stream = new Stream(event.Records[0]);

  // Update list progress when an item is created
  if (stream.isEntity(List)) {
    if (stream.operation === 'insert' && stream.newImage) {
      await ListManager.update(List.getPrimaryKey(stream.newImage.listId), {
        increment: {
          'progress.checked': 1,
        },
      });
    }
  }
}

Type of change:

• Bug fix
• Feature implementation
• Documentation improvement
• Testing improvement
• Something not listed here

Is this a breaking change?

• YES 🚨
• No

Other:

• I have searched through the GitHub pull requests to ensure this PR has not already been submitted
• I have updated the Dynamode documentation (if required)
• I have added/updated the Dynamode test cases (if required)
• I agree that all changes made in this pull request may be distributed and are made available in accordance with the Dynamode License.