fix: always export path in linegraphs in unix style for OS interoperability

Author: pmbittner

src/main/java/org/variantsync/diffdetective/diff/difftree/serialize/treeformat/CommitDiffDiffTreeLabelFormat.java

@@ -1,5 +1,6 @@
 package org.variantsync.diffdetective.diff.difftree.serialize.treeformat;
 
+import org.apache.commons.io.FilenameUtils;
 import org.variantsync.diffdetective.diff.CommitDiff;
 import org.variantsync.diffdetective.diff.PatchDiff;
 import org.variantsync.diffdetective.diff.difftree.CommitDiffDiffTreeSource;
@@ -32,10 +33,10 @@ public DiffTreeSource fromLabel(final String label) {
     public String toLabel(final DiffTreeSource diffTreeSource) {
         if (diffTreeSource instanceof CommitDiffDiffTreeSource commitDiffDiffTreeSource) {
             // write for instances of CommitDiffDiffTreeSources
-            return commitDiffDiffTreeSource.getFileName() + LineGraphConstants.TREE_NAME_SEPARATOR + commitDiffDiffTreeSource.getCommitHash();
+            return FilenameUtils.separatorsToUnix(commitDiffDiffTreeSource.getFileName().toString()) + LineGraphConstants.TREE_NAME_SEPARATOR + commitDiffDiffTreeSource.getCommitHash();
         } else if (diffTreeSource instanceof PatchDiff patchDiff) {
             // write for instances of PatchDiffs
-            return patchDiff.getFileName() + LineGraphConstants.TREE_NAME_SEPARATOR + patchDiff.getCommitDiff().getCommitHash();
+            return FilenameUtils.separatorsToUnix(patchDiff.getFileName()) + LineGraphConstants.TREE_NAME_SEPARATOR + patchDiff.getCommitDiff().getCommitHash();
         } else {
             throw new UnsupportedOperationException("There is no implementation for this DiffTreeSource type: " + diffTreeSource);
         }