As an enhancement to https://github.com/localstack/localstack/pull/1194

It would be really helpful to send the Lambda name, either as data, a header, or as part of the URL.

At code location: https://github.com/localstack/localstack/blob/03c6f4bf250edd18eb818ed65090f508636b0bff/localstack/services/awslambda/lambda_api.py#L696

I can likely open a PR to handle this given some feedback on the feature and potential design.

Right now all I see is the following (using `npx http-echo-server`):
```
[socket#8] event: data
--> POST / HTTP/1.1
--> Host: 192.168.1.x:3000
--> User-Agent: python-requests/2.22.0
--> Accept-Encoding: gzip, deflate
--> Accept: */*
--> Connection: keep-alive
--> Content-Length: 9
--> Content-Type: application/x-www-form-urlencoded
-->
-->
[socket#8] event: data
--> Name=test
```
zip_file=archive, runtime=LAMBDA_RUNTIME_JAVA8,
                                            handler='cloud.localstack.sample.LambdaHandlerWithLib')
            result = self.lambda_client.invoke(FunctionName=lambda_name, Payload=b'{"echo":"echo"}')
            result_data = result['Payload'].read()
            self.assertEqual(result['StatusCode'], 200)
            self.assertIn('echo', to_str(result_data))
            
            testutil.delete_lambda_function(lambda_name)
    def test_sns_event(self):
        result = self.lambda_client.invoke(
            FunctionName=TEST_LAMBDA_NAME_JAVA, InvocationType='Event',
            Payload=b'{"Records": [{"Sns": {"Message": "{}"}}]}')
        self.assertEqual(result['StatusCode'], 202)
    def test_ddb_event(self):
        result = self.lambda_client.invoke(
            FunctionName=TEST_LAMBDA_NAME_JAVA, InvocationType='Event',
            Payload=b'{"Records": [{"dynamodb": {"Message": "{}"}}]}')
        self.assertEqual(result['StatusCode'], 202)
    def test_kinesis_invocation(self):
        result = self.lambda_client.invoke(
            FunctionName=TEST_LAMBDA_NAME_JAVA,
            Payload=b'{"Records": [{"Kinesis": {"Data": "data", "PartitionKey": "partition"}}]}')
        result_data = result['Payload'].read()
        self.assertEqual(result['StatusCode'], 200)
        self.assertIn('KinesisEvent', to_str(result_data))
    def test_kinesis_event(self):
        result = self.lambda_client.invoke(
            FunctionName=TEST_LAMBDA_NAME_JAVA, InvocationType='Event',
            Payload=b'{"Records": [{"Kinesis": {"Data": "data", "PartitionKey": "partition"}}]}')
        result_data = result['Payload'].read()