feat(bindings): tspatial direction predicates (above/below/front/back/left/right + over* variants)

[estebanzimanyi]

Summary

Adds ScalarFunction registrations for tgeompoint × {STBox, tgeompoint} direction predicates wrapping MEOS *_tspatial_stbox / *_stbox_tspatial / *_tspatial_tspatial. 36 registrations total (12 directions × 3 type-pair shapes).

Direction	Operator	Named function
left / right	<< / >>	—
overleft / overright	&< / &>	—
above / below	—	above(...) / below(...)
front / back	—	front(...) / back(...)
overabove / overbelow	—	overabove(...) / overbelow(...)
overfront / overback	—	overfront(...) / overback(...)

The above/below/front/back operators in MobilityDB (|>>, <<|, <</, />>, &</, /&>, etc.) contain | and / characters that DuckDB's parser does not accept inside operator names, so those use named functions instead.

Each direction emits 3 wrappers via DEFINE_TSPATIAL_STBOX_POS(name, meos_fn):

• name##_tspatial_stbox
• name##_stbox_tspatial
• name##_tspatial_tspatial

These reuse the existing TempBoxBoolPred<STBox> / BoxTempBoolPred<STBox> / TempTempBoolPred helpers — STBox blob layout matches the templated Box* malloc/memcpy path used for TBox.

Semantics

• above / below operate on the Y axis
• left / right on the X axis
• front / back on the Z axis (require 3D Point Z(x y z) or STBox Z(...))

Test plan

• Smoke test all 12 directions × 3 type-pair shapes locally; results match expectation
• Full suite passes net of pre-existing TZ-environment failures on WSL2 (same set of failures occurs on PR feat(bindings): tnumber position predicates (<<, >>, &<, &>) #38 base unchanged)