Documentation comment alignment when generated to java

[tomb50]

When generating kernel concepts that have documentation attached, the resulting code comments in the Java code are misaligned (and in cases also duplicated).

Screenshot attached below, tested on maintenance/20223

[alexanderpann]

Could be related to https://youtrack.jetbrains.com/issue/MPS-37979/Generator-COPYSRC-macro-duplicates-smodel-attributes