Fix SELECT * for Pojo queries #18831
Description
Rows generated from Pojos are based on field indices. Which means they can break if Pojo fields are enumerated in a different order. Which can cause generated Row to be different for different runner instance. Which can cause SELECT * to fail.
One solution is to make Pojo field ordering deterministic, e.g. sort them before generating field accessors.
Imported from Jira BEAM-4163. Original Jira may contain additional context.
Reported by: kedin.