Fix ALTER SUBSCRIPTION grammar ambiguity

There was a grammar ambiguity between SET PUBLICATION name REFRESH and
SET PUBLICATION SKIP REFRESH, because SKIP is not a reserved word.  To
resolve that, fold the refresh choice into the WITH options.  Refreshing
is the default now.

Reported-by: tushar <tushar.ahuja@enterprisedb.com>

src/include/nodes/parsenodes.h

@@ -3382,7 +3382,6 @@ typedef enum AlterSubscriptionType
 	ALTER_SUBSCRIPTION_OPTIONS,
 	ALTER_SUBSCRIPTION_CONNECTION,
 	ALTER_SUBSCRIPTION_PUBLICATION,
-	ALTER_SUBSCRIPTION_PUBLICATION_REFRESH,
 	ALTER_SUBSCRIPTION_REFRESH,
 	ALTER_SUBSCRIPTION_ENABLED
 } AlterSubscriptionType;