[Feature] Add Support for Custom Map Indexing with map_index_template

[su-four]

Description

Airflow provides the ability to override the default integer index for mapped tasks in the UI by assigning a custom name based on the task's input. This is achieved using the map_index_template parameter, which allows a Jinja template to dynamically generate the index based on the expanded task's inputs.

.expand(my_param=["value1", "value2", "value3"], map_index_template="{{ my_param }}")  

In this configuration, the task instances would appear in the UI with names based on the my_param values (e.g., value1, value2, value3) instead of default numerical indices (0, 1, 2).(how it is done in airflow)

Use case/motivation

Add support in dag-factory to define and utilize map_index_template in the YAML configuration. This would allow users to customize the indexing of mapped tasks for better readability and debugging in the Airflow UI.

Benefits:

1. Improves clarity and debugging by displaying meaningful indices in the Airflow UI.
2. Aligns dag-factory with Airflow's native features for dynamic task mapping.
3. Enhances usability for workflows where task parameters carry significant context.