Fix SQLUtils.splitSqlScript: keep semicolons after END when semicolon is not the statement separator

[inponomarev]

This PR continues to stabilize ScriptUtils.splitSqlScript after major rework in #7646 and bug fixes in #7818

Problem

Currently in scripts for Oracle, where / is typically used as a statement separator, top-level BEGIN...END blocks are stripped from the semicolon. But unlike other databases, Oracle requires that semicolon is present, otherwise a syntax error occurs.

Input	Current (incorrect) output	Expected output
BEGIN -- do something END; / BEGIN -- do something else END;	BEGIN -- do something END BEGIN -- do something else END	BEGIN -- do something END; BEGIN -- do something else END;

This behaviour occurs because of a misplaced line of code

This PR does not change the original behaviour of "recognizing" top-level BEGIN...END blocks when a specific statement separator is not set, i. e.

Input	Current (correct) output
BEGIN -- do something END; BEGIN -- do something else END;	BEGIN -- do something END BEGIN -- do something else END

[eddumelendez]

Thanks again for your contribution, @inponomarev !