Support DuckDB spatial and shapefile uploads

[philippjfr]

Adds support for loading DuckDB spatial columns and allows uploading shapefiles.

• [x] Check that uploaded zipfile actually contains shapefile data
• [x] Support other geometry file types

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 9.52381% with 38 lines in your changes missing coverage. Please review.

Project coverage is 55.81%. Comparing base (b777a29) to head (5bae144). Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
lumen/ai/controls.py	0.00%	30 Missing :warning:
lumen/sources/duckdb.py	50.00%	4 Missing :warning:
lumen/ai/agents.py	0.00%	2 Missing :warning:
lumen/ai/assistant.py	0.00%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #715 +/- ## ========================================== - Coverage 55.94% 55.81% -0.14% ========================================== Files 98 98 Lines 11845 11879 +34 ========================================== + Hits 6627 6630 +3 - Misses 5218 5249 +31 ```

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