**Description**

Currently `BaseOperator` and `XComArgs` implements the same logic of `__lshift__`, `__rshift__` and others "chain" operations (`>>`, `<<`). It seems resonable to abstract this logic into `TaskMixin` to introduce some DRYness especially because the new concept of `TaskGroup` will also implement the same methods.

**Use case / motivation**

Limit duplication of logic.

**Related Issues**

https://github.com/apache/airflow/pull/10827#issuecomment-691927501
#10153 

airflow/models/baseoperator.py
d=dag.dag_id if dag else "", t=task_id, tr=trigger_rule))
        self.trigger_rule = trigger_rule
        self.depends_on_past = depends_on_past
        self.wait_for_downstream = wait_for_downstream
        if wait_for_downstream:
            self.depends_on_past = True
        self.retries = retries
        self.queue = queue
        self.pool = Pool.DEFAULT_POOL_NAME if pool is None else pool
        self.pool_slots = pool_slots
        if self.pool_slots < 1:
            raise AirflowException("pool slots for %s in dag %s cannot be less than 1"
                                   % (self.task_id, dag.dag_id))
        self.sla = sla
        self.execution_timeout = execution_timeout
        self.on_execute_callback = on_execute_callback
        self.on_failure_callback = on_failure_callback
        self.on_success_callback = on_success_callback
        self.on_retry_callback = on_retry_callback
        if isinstance(retry_delay, timedelta):
            self.retry_delay = retry_delay
        else:
            self.log.debug("Retry_delay isn't timedelta object, assuming secs")
            self.retry_delay = timedelta(seconds=retry_delay)  
        self.retry_exponential_backoff = retry_exponential_backoff
        self.max_retry_delay = max_retry_delay
        self.params = params or {}  
        self.priority_weight = priority_weight
        if not WeightRule.is_valid(weight_rule):
            raise AirflowException(