`head_object` or an async way to check if object exists in an S3 bucket.

[etep]

Description

Using boto3, one can check if an object exists in a bucket using method head_object, see, e.g.: https://stackoverflow.com/questions/33842944/check-if-a-key-exists-in-a-bucket-in-s3-using-boto3

The head_object method does not appear to be implemented in aioboto3.