revert r412961 - it wasn't working as designed and the test failed in a clean environment. The TODO is meant to indicate to replace the parsing of the filename to obtain snapshot metadata with retrieving it from the source metadata file instead of attempting to merge all. The tests did not test snapshot metadata at all.
maven/repository-manager/trunk/maven-repository-converter/src/main/java/org/apache/maven/repository/converter/DefaultRepositoryConverter.java
maven/repository-manager/trunk/maven-repository-converter/src/test/source-modern-repository/test/correctArtifactMetadata/