ML in SE: add more test cases for identifier splitting function

GitOrigin-RevId: d9e4e1693d17b97efb1db013db912fb6abbbd560

platform/ml-embeddings/tests/src/com/intellij/platform/ml/embeddings/utils/IndexingUtilsTest.kt

@@ -24,6 +24,8 @@ class IndexingUtilsTest {
       " with whitespace in front" to "with whitespace in front",
       "with whitespace in back " to "with whitespace in back",
       "multiple   spaces" to "multiple spaces",
+      "path/with/multiple/foldersUnderEachOther" to "path with multiple folders Under Each Other",
+      "register..." to "register",
     )
 
     for ((input, expected) in cases) {