feat(bindings): tgeompoint round-trip I/O — Binary/EWKB/HexWKB/HexEWKB/MFJSON

[estebanzimanyi]

Closes the user-facing round-trip I/O surface for tgeompoint so users can serialise temporal points across formats and reconstruct them.

New SQL surface (16 scalar registrations)

Producers

Signature	Routed through
`asBinary(tgeompoint)` -> bytea	`temporal_as_wkb`, base WKB
`asEWKB(tgeompoint)` -> bytea	`temporal_as_wkb`, `WKB_EXTENDED` with SRID
`asHexWKB(tgeompoint)` -> text	`temporal_as_hexwkb`, base
`asHexEWKB(tgeompoint)` -> text	`temporal_as_hexwkb`, `WKB_EXTENDED`
`asMFJSON(tgeompoint[, with_bbox[, flags[, precision[, srs]]]])` -> text	`temporal_as_mfjson` — 5 overloads

Consumers

Signature	Routed through
`tgeompointFromText(text)` -> tgeompoint	`tgeompoint_in`
`tgeompointFromEWKT(text)` -> tgeompoint	`tgeompoint_in` — auto-detects EWKT prefix
`tgeompointFromBinary(bytea)` -> tgeompoint	`temporal_from_wkb`
`tgeompointFromEWKB(bytea)` -> tgeompoint	`temporal_from_wkb` — auto-detects
`tgeompointFromHexWKB(text)` -> tgeompoint	`temporal_from_hexwkb`
`tgeompointFromHexEWKB(text)` -> tgeompoint	`temporal_from_hexwkb` — auto-detects
`tgeompointFromMFJSON(text)` -> tgeompoint	`tgeompoint_from_mfjson`

The `From*` aliases that share an underlying handler (e.g. FromBinary / FromEWKB) work because MEOS's WKB / hex-WKB readers auto-detect the format byte; the dual registrations are for SQL-name parity with MobilityDB.

Hooked into `LoadInternal` via a new `RegisterRoundtripIO` method on `TgeompointType`.

Tests

• `test/sql/parity/053_tgeompoint_io.test` — 14 assertions covering producer non-empty output, all 7 round-trip pairs (Binary/EWKB/HexWKB/HexEWKB/MFJSON/Text/EWKT), and asMFJSON with optional `with_bbox` / `flags` / `precision` / `srs` args.
• Full suite: 766 assertions / 14 test cases passing under `TZ=UTC`.

Coverage delta

Per the audit in PR #66:

• `geo/053_tpoint_inout` was at 17%; closes the user-facing producer + tgeompointFrom* surface. Remaining names in this section are tgeogpoint (deferred — geographic variant out of scope per current sweep) and a few PG-internal helpers.

Test plan

• `cmake --build . --target shell unittest` clean
• New parity test passes (14/14)
• Full suite green (766/14)

[estebanzimanyi]

Superseded by the consolidated PR branch consolidate/io-serialization-parity.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