feat: Add Geometry & Geography Types (#2859)

Closes #1820

# Rationale for this change

Apache Iceberg v3 introduces native `geometry` and `geography` primitive
types.
This PR adds spec-compliant support for those types in PyIceberg,
including:

- New primitive types with parameter handling and format-version
enforcement
- Schema parsing and round-trip serialization
- Avro mapping using WKB bytes
- PyArrow / Parquet integration with version-aware fallbacks
- Unit test coverage for type behavior and compatibility constraints

A full design and scope discussion is available in the accompanying RFC:
📄 **RFC: [Iceberg v3 Geospatial Primitive
Types](https://github.com/apache/iceberg-python/issues/3004)**
The RFC documents scope, non-goals, compatibility constraints, and known
limitations.

# Are these changes tested?

Yes.

- Unit tests cover:
  - Type creation (default and custom parameters)
  - `__str__` / `__repr__` round-tripping
  - Equality, hashing, and pickling
  - Format version enforcement (v3-only)
- PyArrow-dependent behavior is version-gated and conditionally tested

# Are there any user-facing changes?

Yes.

- Users may now declare `geometry` and `geography` columns in Iceberg v3
schemas
- Parquet files written with PyArrow ≥ 21 preserve GEO logical types
when available
- Limitations (e.g. no WKB↔WKT conversion, no spatial predicates) are
documented

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