Refactor parsing rules for option lists of EXPLAIN, VACUUM and ANALYZE
Those three commands have been using the same grammar rules to handle a
a list of parenthesized options. This refactors the code so as they use
the same parsing rules, shaving some code. A future commit will make
use of those option parsing rules for more utility commands, like
REINDEX and CLUSTER.
Author: Alexey Kondratov, Justin Pryzby
Discussion: https://postgr.es/m/
8a8f5f73-00d3-55f8-7583-
1375ca8f6a91@postgrespro.ru