**Description**

It would be great having a option to abort a DAG Runs through the REST API.

**Use case / motivation**

The proposed input params would be:
 - DAG_ID
 - DAG_RUN_ID

The DAG Run should abort all its tasks running and mark them as "failed".

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

**Related Issues**


airflow/api_connexion/schemas/dag_run_schema.py
"""Auto generate run_id and logical_date if they are not provided.
        For compatibility, if `execution_date` is submitted, it is converted
        to `logical_date`.
        """
        logical_date = data.get("logical_date", _MISSING)
        execution_date = data.pop("execution_date", _MISSING)
        if logical_date is execution_date is _MISSING:  
            data["logical_date"] = str(timezone.utcnow())
        elif logical_date is _MISSING:  
            data["logical_date"] = execution_date
        elif execution_date is _MISSING:  
            pass
        elif logical_date != execution_date:  
            raise BadRequest(
                "logical_date conflicts with execution_date",
                detail=f"{logical_date!r} != {execution_date!r}",
            )
        if "dag_run_id" not in data:
            try:
                data["dag_run_id"] = DagRun.generate_run_id(
                    DagRunType.MANUAL, timezone.parse(data["logical_date"])
                )
            except (ParserError, TypeError) as err:
                raise BadRequest("Incorrect datetime argument", detail=str(err))
        return data
    @post_dump
    def autofill(self, data, **kwargs):