feat(bindings): asMVTGeom + geoMeasure for tgeompoint

[estebanzimanyi]

Closes the visualization-essential analytics in `geo/076_tpoint_analytics` so users can encode trajectories for Mapbox Vector Tile rendering and add a measure dimension (M-coord) from a parallel `tfloat`.

New SQL surface (6 scalar registrations)

Signature	Returns	Routed through
`asMVTGeom(tgeompoint, stbox)`	`STRUCT(geom GEOMETRY, times BIGINT[])`	`tpoint_as_mvtgeom` (extent=4096, buffer=256, clip=TRUE defaults)
`asMVTGeom(tgeompoint, stbox, integer)`	same	+ custom extent
`asMVTGeom(tgeompoint, stbox, integer, integer)`	same	+ custom extent + buffer
`asMVTGeom(tgeompoint, stbox, integer, integer, boolean)`	same	full args
`geoMeasure(tgeompoint, tfloat)`	`GEOMETRY`	`tpoint_tfloat_to_geomeas` (segmentize=FALSE default)
`geoMeasure(tgeompoint, tfloat, boolean)`	`GEOMETRY`	full args

Implementation notes

asMVTGeom

Output is a single-row composite `STRUCT(geom GEOMETRY, times BIGINT[])` matching MobilityDB's `geom_times` type. MEOS hands back one clipped/projected geometry plus a parallel array of Unix-epoch second timestamps (one per vertex). The exec function:

• Calls `tpoint_as_mvtgeom(temp, bounds, extent, buffer, clip, &geom, &times, &count)`.
• Encodes the GSERIALIZED geometry into the struct's `geom` child via `GSerializedToGeometry` (with an `ArenaAllocator` scoped to the result vector).
• Materialises the int64 timestamp array into the `BIGINT[]` struct child via standard `ListVector` reserve/set patterns.

geoMeasure

Routes `tpoint_tfloat_to_geomeas(tpoint, measure, segmentize, &geom)` and encodes the resulting GSERIALIZED with M-coord via `GSerializedToGeometry`.

Both are scalar functions, no TableFunction infra required.

Tests

• `test/sql/parity/076_asmvtgeom_geomeasure.test` — 6 assertions covering the `typeof` shape, default-extent and custom-extent encodings, times-array length, and both geoMeasure overloads (with/without segmentize).
• Full suite: 758 assertions / 14 test cases passing under `TZ=UTC`.

Coverage delta

Per the audit in PR #66:

• `geo/076_tpoint_analytics` and `geo/076_tgeo_analytics`: `asMVTGeom` and `geoMeasure` were the visualization-blocking gaps. Now covered.

Test plan

• `cmake --build . --target shell unittest` clean
• New parity test passes (6/6)
• Full suite green (758/14)

[estebanzimanyi]

Superseded by the consolidated PR branch consolidate/tgeompoint-ops-parity.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.