feat(bindings): ever/always equality and inequality (eq, ne) — named functions

[estebanzimanyi]

Summary

Adds 36 ScalarFunction registrations covering the temporal-comparison ever/always surface for tbool / tint / tfloat:

Function	Variants
ever_eq, always_eq, ever_ne, always_ne	value op temporal, temporal op value, temporal op temporal × {bool/tbool, int/tint, double/tfloat}

DuckDB's parser does not accept ? or # as operator-name characters, so the upstream MobilityDB operators ?=, ?<>, #=, #<> are unreachable from SQL — these named functions provide equivalent behaviour.

Implementation

• 28 wrapper functions (4 named functions × 7 type-pair shapes) generated via a DEFINE_EA_OP macro that calls the matching MEOS function.
• 3 small templated helpers (EverAlwaysValTemp, EverAlwaysTempVal, EverAlwaysTempTemp).
• MEOS returns int (1=true, 0=false, -1=null/error), mapped to bool via r > 0.

Out of scope (follow-up)

• ttext_text / text_ttext variants (would need PG-text encoding plumbing)
• Ordering ops (ever_lt, always_lt, etc.) — same shape; can extend the DEFINE_EA_OP macro

Smoke test

SELECT ever_eq(1, tint '[1@01-01, 2@01-02]');                  -- true
SELECT always_eq(tint '[1@01-01, 1@01-02]', 1);                -- true
SELECT ever_ne(tint '[1@01-01, 2@01-02]', 1);                  -- true
SELECT always_ne(tint '[1@01-01, 2@01-02]', 5);                -- true
SELECT ever_eq(tbool '[t@01-01, f@01-02]', true);              -- true
SELECT ever_eq(tfloat '[1.5@01-01, 2.5@01-02]', 2.0::DOUBLE);  -- true

Test plan

• make release then TZ=UTC ./build/release/test/unittest "<proj>/test/*" — full suite passes.
• After merge, PR test(parity): batch 2 — boolops / textfuncs / compops / posops / aggfuncs #24's 030_temporal_compops.test skip block partially unwraps (the eq/ne queries become active when re-pointed from ?= / #= to ever_eq / always_eq etc.). Ordering ops stay separate follow-up.

Dependencies

Stacked on PR #33 (temporal time-position predicates). Merge order: #27 → #29 → #30 → #31 → #32 → #33 → this.

[estebanzimanyi]

Consolidated into #41 (ever/always comparison predicates — eq/ne/ord combined).