Add mapstruct-processor to annotation processor paths when Lombok and MapStruct are used

[timtebeek]

• Fixes Java 17 - Lombok Annotation Processors - include mapstruct #1174

Problem

When a project uses both Lombok and MapStruct, UpgradeToJava17 (via AddLombokMapstructBinding + EnableLombokAnnotationProcessor) adds the lombok-mapstruct-binding and lombok annotation processor paths, but never adds mapstruct-processor. Without it on the annotation processor path, MapStruct generates no mapper code once annotation processing is configured explicitly (required from Java 23 onward).

Fix

New recipe org.openrewrite.java.migrate.AddMapstructAnnotationProcessorPath, wired into AddLombokMapstructBinding. It:

• discovers the resolved org.mapstruct:mapstruct version, and
• adds a mapstruct-processor <path> to the maven-compiler-plugin annotationProcessorPaths at that same version.

It reuses the upstream org.openrewrite.maven.AddAnnotationProcessor for the actual insertion (so multi-module placement, "already configured" detection, and maven-compiler-plugin 3.12+ managed-version handling all carry over), supplying the version discovered during the scan phase. No-op when MapStruct isn't present.

Tests

• AddLombokMapstructBindingTest: new addMapstructProcessorForMaven; existing Maven cases updated to include the new path; doesNotDuplicateMaven extended to assert idempotency for the mapstruct-processor path too. Gradle cases are unaffected (the recipe is Maven-only).
• UpgradeToJava17Test: new addsMapstructProcessorWhenLombokAndMapstructUsedWithoutAnnotationProcessorPaths exercising the full chain from the issue — mapstruct-processor is added and tracks the upgraded MapStruct 1.6.x version.