### 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
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    @property
    def current_path(self):
        return self._refpaths[-1]
    @contextlib.contextmanager
    def _pathctx(self, refpath: str):
        if not self._is_internal_ref(refpath):
            refpath = "/".join((self.current_path, refpath))
        self._refpaths.append(refpath)
        yield
        self._refpaths.pop()
    def _resolve_refpath(self, refpath: str) -> dict:
        if refpath in self._refpaths and not self.allow_recursive:
            raise Exception("recursion detected with allow_recursive=False")
        if refpath in self._cache:
            return self._cache.get(refpath)
        with self._pathctx(refpath):
            if self._is_internal_ref(self.current_path):
                cur = self.document
            else:
                raise NotImplementedError("External references not yet supported.")
            for step in self.current_path.split("/")[1:]:
                cur = cur.get(step)
            self._cache[self.current_path] = cur
            return cur
    def _namespaced_resolution(self, namespace: str, data: Union[dict, list]) -> Union[dict, list]:
        with self._pathctx(namespace):
            return self._resolve_references(data)
    def _resolve_references(self, data) -> Union[dict, list]: