<!--

Welcome to Apache Airflow!  For a smooth issue process, try to answer the following questions.
Don't worry if they're not all applicable; just try to include what you can :-)

If you need to include code snippets or logs, please put them in fenced code
blocks.  If they're super-long, please use the details tag like
<details><summary>super-long log</summary> lots of stuff </details>

Please delete these comment blocks before submitting the issue.

-->

**Description**

<!-- A short description of your feature -->

Make `MongoToS3Operator` `mongo_collection` parameter templated.

**Use case / motivation**

<!-- What do you want to happen?

Rather than telling us how you might implement this solution, try to take a
step back and describe what you are trying to achieve.

-->

This would allow for passing a templated mongo collection from other tasks, such as a mongo collection used as data destination by using `S3Hook`. For instance, we could use templated mongo collection to write data for different dates in different collections by using: `mycollection.{{ ds_nodash }}`.

**Are you willing to submit a PR?**

<!--- We accept contributions! -->

Yes.

**Related Issues**

<!-- Is there currently another issue associated with this? -->

N/A

airflow/providers/amazon/aws/transfers/mongo_to_s3.py
"""
        Takes an iterable (pymongo Cursor or Array) containing dictionaries and
        returns a stringified version using python join
        """
        return joinable.join([json.dumps(doc, default=json_util.default) for doc in iterable])
    @staticmethod
    def transform(docs: Any) -> Any:
        """
        Processes pyMongo cursor and returns an iterable with each element being
                a JSON serializable dictionary
        Base transform() assumes no processing is needed
        ie. docs is a pyMongo cursor of documents and cursor just
        needs to be passed through
        Override this method for custom transformations
        """
        return docs