Fix multiline delegated constructor formatting

[arpitagarwal1301]

Fixes #1762

Summary

• expand delegated this(...) and super(...) calls when an argument contains an explicit structural newline
• indent every expanded argument and emit Kotlin-style trailing commas
• preserve existing one-line calls and %S/%P string data, including trailing newlines

This independently reimplements the behavior previously reviewed in #2332, which was closed because its author could not complete the Square CLA. No commits were copied.

Validation

• focused red-then-green delegate-constructor and CodeBlock regressions
• ./gradlew spotlessApply :kotlinpoet:spotlessKotlinCheck :kotlinpoet:apiCheck :kotlinpoet:jvmTest
• ./gradlew clean build with Zulu OpenJDK 26.0.2
• git diff --check