Make JDT path resolution pluggable for compiled JsonPath support

Thread a pathResolver function through the JDT engine so callers can
plug in bytecode-compiled JsonPath queries instead of the interpreter.

The new overload Jdt.transform(source, transform, pathResolver) accepts
a Function<String, Function<JsonValue, List<JsonValue>>> that compiles
a JsonPath expression into a query function.

Default behavior unchanged: uses JsonPath.parse(expr)::query.

Example with compiled JsonPath:
  Jdt.transform(source, transform, expr -> JsonPathCodegen.compile(expr)::query);

All 33 existing tests pass unchanged.

To verify: mvn test -pl json-java21-jdt -am

Author: simbo1905