Fixed marshalling & unmarshalling edge cases

[nkvuong]

• Return empty list/dict instead of returning None in some edge cases
• Add an extra test case to verify

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 62.50000% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 78.52%. Comparing base (942c52e) to head (853a177).

Files	Patch %	Lines
src/databricks/labs/blueprint/installation.py	62.50%	1 Missing and 2 partials :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #76 +/- ## ========================================== + Coverage 78.50% 78.52% +0.01% ========================================== Files 14 14 Lines 1447 1448 +1 Branches 256 256 ========================================== + Hits 1136 1137 +1 Misses 224 224 Partials 87 87 ```

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