Add TaskGroup support

[jlaneve]

closes #27

This PR makes a few small changes to support for Airflow TaskGroups in a Databricks workflow:

• it traverses up the tree of task groups to see if the task is in a Databricks Workflow TaskGroup instead of just the immediate parent
• instead of iterating over direct children of the Databricks Workflow TaskGroup, it first flattens the children by recursively removing task groups
• small bugfix in the Tiltfile to fix the dev folder sync
• adds an example dag to the dev directory using TaskGroups

I've run the example DAG in Astronomer's Databricks account, and it worked like a charm! Worth noting that Databricks themselves don't have support for TaskGroups/dependency groups, so this was pretty cool to put together.

Also worth noting that in the process of putting this together, I uncovered a bug I filed to be addressed separately.

[codecov-commenter]

Codecov Report

Patch coverage: 76.66% and project coverage change: -0.55 ⚠️

Comparison is base (0538602) 78.82% compared to head (1ddcdc5) 78.28%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #29      +/-   ##
==========================================
- Coverage   78.82%   78.28%   -0.55%     
==========================================
  Files           5        5              
  Lines         425      442      +17     
  Branches       47       52       +5     
==========================================
+ Hits          335      346      +11     
- Misses         73       76       +3     
- Partials       17       20       +3     

Impacted Files	Coverage Δ
src/astro_databricks/operators/notebook.py	89.52% <63.63%> (-3.19%)	⬇️
src/astro_databricks/operators/workflow.py	83.46% <84.21%> (-0.57%)	⬇️

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