SQL Format Support ON CONFLICT

[xterao]

Support formatting for upsert statements using the ON CONFLICT DO [NOTHING | UPDATE] syntax.
This includes proper indentation and line breaking rules for ON CONFLICT, optional ON CONSTRAINT, and the DO clause with its associated update logic.

[Copilot]

Pull Request Overview

This PR introduces enhanced formatting support for SQL upsert statements using the ON CONFLICT clause. The updates include new test cases for various ON CONFLICT patterns, modifications to how conflict and DO clauses are handled in formatter block utilities, and minor refactoring in test configuration for consistent file naming.

Reviewed Changes

Copilot reviewed 34 out of 38 changed files in this pull request and generated 1 comment.

File	Description
src/test/testData/sql/formatter/InsertConflictUpdate*.sql	Added/updated tests to verify proper formatting of INSERT statements with ON CONFLICT clauses.
src/test/kotlin/org/domaframework/doma/intellij/formatter/SqlFormatterTest.kt	Updated test naming using a new formatDataPrefix variable for consistency.
src/main/kotlin/org/domaframework/doma/intellij/formatter/util/SqlBlockUtil.kt	Introduced and refined formatting handling for conflict-related blocks (e.g. CONFLICT, DO, etc.).
Other Kotlin formatter and block files	Various adjustments and import refactorings to support new conflict clause support in SQL formatting.

Comments suppressed due to low confidence (2)

src/test/kotlin/org/domaframework/doma/intellij/formatter/SqlFormatterTest.kt:30

• [nitpick] Consider adding a brief inline comment explaining the purpose of the formatDataPrefix variable to clarify its role in constructing expected test filenames.

    private val formatDataPrefix = "_format"

src/main/kotlin/org/domaframework/doma/intellij/formatter/block/group/keyword/update/SqlUpdateValueGroupBlock.kt:52

• [nitpick] Consider expanding or updating this TODO comment to indicate a plan for creating a dedicated class for update values to improve clarity and maintainability.

            // TODO Update Values用のクラスを作る