Save tasks map as DbtToAirflowConverter property

[internetcoffeephone]

Description

Currently, if you want to modify a DAG after it has been rendered,
you have to walk through the dag.dbt_graph, then puzzle the task IDs
and task group IDs together by reverse-engineering your task rendering
strategy.

This is cumbersome and error-prone, hence it makes sense to expose the
mapping from DbtNode to Airflow Task ID as a DAG property. This allows
you to walk the DBT graph while directly accessing any corresponding
Airflow tasks, which makes e.g. adding Airflow sensors upstream of all
source tasks much easier.

Breaking Change?

No

Checklist

• I have made corresponding changes to the documentation (if required)
• I have added tests that prove my fix is effective or that my feature works

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.28%. Comparing base (0000f80) to head (7b9ce91).
Report is 4 commits behind head on main.

Additional details and impacted files

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##             main    #1362   +/-   ##
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  Coverage   96.28%   96.28%           
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  Files          68       68           
  Lines        4149     4150    +1     
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+ Hits         3995     3996    +1     
  Misses        154      154           

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[tatiana]

HI @internetcoffeephone, thank you very much for your contribution.

The feature makes sense, and your implementation is very clean and straightforward.

I only have three requests:

• Add a unitest test confirming this new behaviour;
• Create an example DAG illustrating how you can leverage this feature in dev/dags; and
• Either add docs or create an issue so we can address this (we also need to document that graph is exposed, so there is debt on our side).

If you can get these changes before 20 December, we'll release this feature as part of Cosmos 1.8.

[internetcoffeephone]

@tatiana I finally got around to doing this, hopefully I addressed all three points you mentioned.

Wasn't quite sure what to name the docs entry, I think Post-rendering DAG customization is a bit clunky. If you have any better suggestions, I'd be happy to change it.

[tatiana]

Thank you very much for addressing the feedback, @internetcoffeephone , we'll release this on 1.8 this week.