Catastrophic backtracking issue in QueryFormatter

There's a catastrophic backtracking regex issue that reproduces easily when there are too many newlines in the SQL file (as they match both the `\s` and `\n` in the `(\s|\n)+` and result in exponential backtracking).
Because of this, having too many consecutive newlines in any part of a SQL file results in never-ending formatting.

Reproduction and fix is in #6.

首先定位 QueryFormatter 和 issue 中描述的 `(\s|\n)+` 表达式。查看 issue #6 中引用的复现和修复，然后验证包含大量连续换行符的 SQL 能够快速完成格式化，而不会发生灾难性回溯。

由索引模型根据 Issue 内容生成。