Re: remaining sql/json patches

play with domain types.
in ExecEvalJsonCoercion, seems func json_populate_type cannot cope
with domain type.

tests:
drop domain test;
create domain test as int[] check ( array_length(value,1) =2 and
(value[1] = 1 or value[2] = 2));
SELECT * from JSON_QUERY(jsonb'{"rec": "{1,2,3}"}', '$.rec' returning
test omit quotes);
SELECT * from JSON_QUERY(jsonb'{"rec": "{1,11}"}', '$.rec' returning
test keep quotes);
SELECT * from JSON_QUERY(jsonb'{"rec": "{2,11}"}', '$.rec' returning
test omit quotes error on error);
SELECT * from JSON_QUERY(jsonb'{"rec": "{2,2}"}', '$.rec' returning
test keep quotes error on error);

SELECT * from JSON_QUERY(jsonb'{"rec": [1,2,3]}', '$.rec' returning
test omit quotes );
SELECT * from JSON_QUERY(jsonb'{"rec": [1,2,3]}', '$.rec' returning
test omit quotes null on error);
SELECT * from JSON_QUERY(jsonb'{"rec": [1,2,3]}', '$.rec' returning
test null on error);
SELECT * from JSON_QUERY(jsonb'{"rec": [1,11]}', '$.rec' returning
test omit quotes);
SELECT * from JSON_QUERY(jsonb'{"rec": [2,2]}', '$.rec' returning test
omit quotes);

Many domain related tests seem not right.
like the following, i think it should just return null.
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.b' RETURNING sqljsonb_int_not_null);
+ERROR: domain sqljsonb_int_not_null does not allow null values

--another example
SELECT JSON_QUERY(jsonb '{"a": 1}', '$.b' RETURNING
sqljsonb_int_not_null null on error);

Maybe in node JsonCoercion, we don't need both via_io and
via_populate, but we can have one bool to indicate either call
InputFunctionCallSafe or json_populate_type in ExecEvalJsonCoercion.