Support Postgres Explain options

[kysshsy]

support EXPLAIN [ ( option [, ...] ) ] statement , like EXPLAIN (analyze true, option_name option_arg) select * from t1 .
Postgres doc.

in Postgres

explain (analyze true) select * from t100;
                                            QUERY PLAN
--------------------------------------------------------------------------------------------------
 Seq Scan on t100  (cost=0.00..35.50 rows=2550 width=4) (actual time=0.007..0.008 rows=0 loops=1)
 Planning Time: 0.040 ms
 Execution Time: 0.019 ms
(3 rows)

explain (aaa) select * from t100;
ERROR:  unrecognized EXPLAIN option "aaa"
LINE 1: explain (aaa) select * from t100;

I want the parser to handle options in a way similar to how the Postgres parser does. Specifically, I want it to be able to parse key-value pairs and validate them when executing the EXPLAIN command. This would allow users to define and include custom options.