feat(bindings): temporal boxops followups — named-function aliases + tboxes/splitN/splitEachN

[estebanzimanyi]

Closes 7 of 8 missing names in `temporal/032_temporal_boxops` (was 27%; this brings the user-visible surface to ~88%).

New SQL surface

Named-function aliases for the existing topological operators

MobilityDB exposes both the operator and named-function form for each topological predicate. The operator forms (`@>`, `<@`, `&&`, `-|-`) are already wired across all 36 existing overloads; this PR registers the matching named functions against the same handlers.

Operator	Named alias
`@>`	`temporal_contains`
`<@`	`temporal_contained`
`&&`	`temporal_overlaps`
`-	-`

Coverage:

• temporal × temporal (every base-type pair)
• temporal × tstzspan and tstzspan × temporal
• tnumber × numspan / numspan × tnumber
• tnumber × tbox / tbox × tnumber

A small `REG_TOP4` macro factors the tnumber × {numspan, tbox} 4-handler block.

tnumber → LIST(tbox) emitters

Signature	Routed through
`tboxes(tnumber)` -> `LIST(tbox)`	`tnumber_tboxes`
`splitNTboxes(tnumber, integer)` -> `LIST(tbox)`	`tnumber_split_n_tboxes`
`splitEachNTboxes(tnumber, integer)` -> `LIST(tbox)`	`tnumber_split_each_n_tboxes`

What stays unregistered

The 8th missing name, `temporal_same` (alias of `=`), is deferred. The underlying `=` operator handlers (`Same_temporal_temporal`, `Same_tnumber_numspan`, `Same_tnumber_tbox`, `Same_temporal_tstzspan`) are not yet wired in MobilityDuck. Adding them is straightforward MEOS plumbing — one new handler family + a parallel registration block — but warrants a focused PR rather than expanding the surface of this one.

Tests

• `test/sql/parity/032_temporal_boxops_followups.test` — 9 assertions covering the alias-equivalence with operators, the cross-type variants, and the tboxes/splitN/splitEachN list-returning surface.
• Full suite: 761 assertions / 14 test cases passing under `TZ=UTC`.

Coverage delta

Per the audit in PR #66:

• `temporal/032_temporal_boxops`: 3/11 (27%) → 10/11 (91%) by name.

Test plan

• `cmake --build . --target shell unittest` clean
• New parity test passes (9/9)
• Full suite green (761/14)

[estebanzimanyi]

Superseded by the consolidated PR branch consolidate/temporal-ops-parity. All changes from this PR are included in that branch as a single squashed commit. Please review and merge the consolidated branch instead.