Add filtering of XCOMs for Dynamic Task Mapping

### Description Allow filtering mappable XCOMs such that inputs to dynamic task mapping run on a subset of the XCOM. ```python @task def get_integers(): return [-1, 0, 1] @task def print_x(x): print(x) print_x.expand(get_integers().filter(lambda x: x>0)) # Prints: # 1 ``` ### Use case/motivation Currently, this can be implemented with a dedicated task just for filtering. This becomes undesired if you intend to filter to partition the XCOM output as inputs of multiple task (i.e., branching/partitioning): ### Dynamic task branching with XCOM filtering ```python @task def get_integers(): return [-1, 0, 1] @task def print_x(x): print(x) integers = get_integers() task_print_positive = print_x.expand(integers.filter(lambda x: x>0)) task_print_negatives = print_x.expand(integers.filter(lambda x: x<0)) task_print_zeros = print_x.expand(integers.filter(lambda x: x==0)) # The flow logic is effectively: # integers >> [task_print_positive, task_print_negatives, task_print_zeros] ``` ### Dynamic task branching with Taskflow API ```python @task def get_integers(): return [-1, 0, 1] @task def print_x(x): print(x) @task def filter_positive(x): return list(filter(x>0, x)) @task def filter_negative(x): return list(filter(x<0, x)) @task def filter_zero(x): return list(filter(x==0, x)) integers = get_integers() task_print_positive = print_x.expand(filter_positive(integers)) task_print_negatives = print_x.expand(filter_negatives(integers)) task_print_zeros = print_x.expand(filter_zeros(integers)) # The flow logic is effectively: # integers >> [filter_positive >> task_print_positive, filter_negative >> task_print_negatives, filter_zeros >> task_print_zeros] ``` ### Related issues _No response_ ### Are you willing to submit a PR? - [ ] Yes I am willing to submit a PR! ### Code of Conduct - [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)