Investigate usage of ModelTransformer

[laeubi]

Tycho do some transformations of the maven model on several places, Maven 4 offers a ModelTransformer for this purpose https://github.com/apache/maven/blob/665b831c5ec7731016b48f63000f8fc3b0ed0257/api/maven-api-spi/src/main/java/org/apache/maven/api/spi/ModelTransformer.java#L32