[spec] Support parsing REST catalog Predicate and Transform JSON

[plusplusjiajia]

Purpose

Deserialize the REST catalog's serialized Predicate and Transform JSON
(the row filter / column masking a query-auth.enabled table returns) into
spec::Predicate / spec::Transform. Parse-only — needed by the query-auth
enforcement follow-up.

Changes

• Predicate::from_rest_json + collect_leaf_field_indices
• spec::Transform / TransformInput + Transform::from_rest_json +
  collect_field_indices
• Field references resolve by name; the local field type drives literal
  conversion. Tests pin wire strings from Java's PredicateJsonSerdeTest /
  TransformJsonSerdeTest.

Scope

Structural parsing only, following the crate's existing pattern for
REST-serialized payloads (Schema uses #[derive(Deserialize)]; the shared
DataType parser already accepts lenient type strings for schema columns).
It does not replicate the Java parser bit-for-bit:

• CAST is parsed structurally; cast applicability is checked where the mask
  is applied (arrow cast + output-type equality), not here.
• LIKE uses SQL escape semantics; row-filter evaluation reuses the shared
  residual evaluator (arrow/residual.rs), so Float/Double.compareTo and
  LIKE _ edge semantics are Arrow's — a documented limitation

[JingsongLi]

Incompatible with Java legitimate wire format: Java will generate 'LEAF+transform=NULL+function=TRUS/FALSE', which Rust currently explicitly rejects. The result is a failed valid query auth condition (fail closed, not unauthorized, but will erroneously reject the query).

[plusplusjiajia]

Incompatible with Java legitimate wire format: Java will generate 'LEAF+transform=NULL+function=TRUS/FALSE', which Rust currently explicitly rejects. The result is a failed valid query auth condition (fail closed, not unauthorized, but will erroneously reject the query).

@JingsongLi Thanks for catching this! Fixed — TRUE/FALSE leaves with the NULL transform now parse to AlwaysTrue/AlwaysFalse, with the PredicateJsonSerdeTest wire strings pinned in tests.

[JingsongLi]

+1