Add multi-prefix comment support for @SqlConfig

gh-23289 introduced support for multiple single-line comment prefixes
for ScriptUtils, ResourceDatabasePopulator, and EmbeddedDatabaseBuilder.

This commit adds the same support for @SqlConfig in the TestContext
Framework. Specifically, @SqlConfig has a new `commentPrefixes`
attribute for setting multiple single-line comment prefixes.

Closes gh-23331

spring-test/src/test/resources/org/springframework/test/context/jdbc/data-add-users-with-custom-script-syntax.sql

@@ -19,4 +19,7 @@ VALUES('Dilbert')
 
 
 INSERT INTO user VALUES('Dogbert')@@
+
+%% another custom single-line comment
+
 INSERT INTO user VALUES('Catbert')@@