#1043 add map_index_template, fix name->item bug from #1035

[gabrielwol]

What this pull request accomplishes:

• Now that Morbius Airflow is upgraded past 2.9.3 we can implement named mapped tasks (map_index_template)
• See successful test in gcc_pull_layers_bigdata. ✅ (tested without unnecessary update of GIS tables by commenting out parts of pull_layer).
• Also fixed small bug from #1035 (dag_name -> item).

Issue(s) this solves:

• #1043

What, in particular, needs to reviewed:

What needs to be done by a sysadmin after this PR is merged

Update DAG link in Morbius.