Fix formatting for EXISTS clause

[xterao]

Problem

When using the EXISTS clause in SQL conditions, unintended line breaks were inserted. This affected formatting in various scenarios, such as when EXISTS is used as the first condition in a WHERE clause, within conditional directives, or in combination with CREATE or IN clauses.

Solution

A new block class was introduced to represent the EXISTS clause. By properly recognizing the parent-child relationships of these blocks, the formatter now controls line breaks and indentation more accurately.

Testing

• Verified formatting when EXISTS is used as the first condition in a WHERE clause.
• Tested cases where specific keywords are wrapped with conditional directives.
• Checked formatting when EXISTS is combined with CREATE or IN clauses.

[Copilot]

Pull Request Overview

This PR fixes formatting issues with SQL EXISTS clauses by introducing a new block class to properly handle line breaks and indentation. The fix addresses problems where unintended line breaks were inserted when EXISTS appeared as the first condition in WHERE clauses, within conditional directives, or combined with CREATE/IN clauses.

• Introduces SqlExistsGroupBlock to represent EXISTS clauses with proper formatting logic
• Updates block generation logic to recognize EXISTS keywords and create appropriate block structures
• Refactors conditional comment block indentation calculations for better maintainability

Reviewed Changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
SqlExistsGroupBlock.kt	New block class implementing EXISTS clause formatting with specialized indentation logic
SqlKeywordUtil.kt	Adds EXISTS keyword recognition and line setting rules
SqlBlockGenerator.kt	Updates block generation to handle EXISTS keywords and create SqlExistsGroupBlock instances
SqlElConditionLoopCommentBlock.kt	Refactors indentation calculation methods for better maintainability and adds directive support
SqlSubQueryGroupBlock.kt	Improves child block filtering logic for conditional comments and keyword groups
Test files	Adds comprehensive test cases for conditional EXISTS and subquery formatting scenarios

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