### Is there an existing issue for this?

- [X] I have searched the existing issues

### Feature description

Basically we want to only run the lambda when an insert is occurring in DynamoDB.
I tested using Dynobase deleting a record and the lambda still triggered.

```
resource "aws_lambda_event_source_mapping" "event-log" {
	event_source_arn  = aws_dynamodb_table.event-log.stream_arn
	function_name     = module.main.lambda-arn
	starting_position = "LATEST"
	enabled = true # change to false when truncating the table in localstack
	maximum_retry_attempts = 1 # limit retry on failure to 1 for now

	# https://dev.to/aws-builders/filtering-dynamodb-streams-before-lambda-p5p
	filter_criteria { # Doesn't seem to work on LocalStack for now
		filter {
			pattern = jsonencode({
				body = {
					eventName : ["INSERT"]
				}
			})
		}
	}
}
```


### 🧑‍💻 Implementation

_No response_

### Anything else?

 https://dev.to/aws-builders/filtering-dynamodb-streams-before-lambda-p5p
temp_mv_dict = defaultdict(list)
    for key in elements:
        if isinstance(key, (list, tuple)):
            key, value = key
        else:
            value = elements[key]
        key = to_str(key)
        temp_mv_dict[key].append(value)
    return dict((k, tuple(v)) for k, v in temp_mv_dict.items())
def get_lambda_runtime(runtime_details: Union[LambdaFunction, str]) -> str:
    """Return the runtime string from the given LambdaFunction (or runtime string)."""
    if isinstance(runtime_details, LambdaFunction):
        runtime_details = runtime_details.runtime
    if not isinstance(runtime_details, str):
        LOG.info("Unable to determine Lambda runtime from parameter: %s", runtime_details)
    return runtime_details or ""
def is_provided_runtime(runtime_details: Union[LambdaFunction, str]) -> bool:
    """Whether the given LambdaFunction uses a 'provided' runtime."""
    runtime = get_lambda_runtime(runtime_details) or ""
    return runtime.startswith("provided")
def format_name_to_path(handler_name: str, delimiter: str, extension: str):