Add durability to Databricks Lakeflow

[yaron2]

This PR adds an extension that turns Databricks Lakeflow data into durable business actions without building your own retry-safe orchestration layer.

dapr.ext.databricks fixes this with one function call:

• One line, register_workflow_sink(...), turns any Lakeflow streaming table into a trigger for a durable Dapr Workflow - retries, timers, human approval steps, and multi-day processes, all running independently of your pipeline.
• Retry- and refresh-safe by default. Every action gets a deterministic, collision-safe identity, so a Lakeflow micro-batch retry - or a full pipeline refresh - is automatically recognized as "already handled," never
  re-triggered.
• Decouples fast ingestion from slow business logic. A workflow that waits three days for a human doesn't hold up your streaming pipeline for a second - Lakeflow hands off and moves on.

[codecov]

Codecov Report

❌ Patch coverage is 98.77049% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.68%. Comparing base (74c3c54) to head (5ae1cb8).

Files with missing lines	Patch %	Lines
dapr/ext/databricks/batch_handler.py	97.14%	2 Missing ⚠️
dapr/ext/databricks/identity.py	97.91%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1223      +/-   ##
==========================================
+ Coverage   83.32%   83.68%   +0.35%     
==========================================
  Files         123      132       +9     
  Lines       10250    10494     +244     
==========================================
+ Hits         8541     8782     +241     
- Misses       1709     1712       +3     

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