Fix wrong unit by label indexin in Qudt (#124)

- QUDT now uses the correct trie prefix for labels when indexing units
- Adds a unit test that activated the bug prior to fixing it

Author: fkleedorfer

qudtlib-main/src/main/java/io/github/qudtlib/Qudt.java

@@ -165,7 +165,7 @@ private static void reindexUnitsForSearch() {
                     .map(LangString::getString)
                     .forEach(
                             s -> {
-                                unitIndex.put(UNIT_INDEX_KEYS.UCUM_CODE + s, u);
+                                unitIndex.put(UNIT_INDEX_KEYS.LABEL + s, u);
                             });
         }
     }

qudtlib-test/src/test/java/io/github/qudtlib/QudtTests.java

@@ -1004,6 +1004,8 @@ private void testParseUnit(String input, QuantityKind quantityKind, Set<Unit> ex
 
     public static Stream<Arguments> testParseUnit_specificCases() {
         return Stream.of(
+                Arguments.of("g/Mole", QuantityKinds.MolarMass, Set.of(Units.GM__PER__MOL)),
+                Arguments.of("g/mole", QuantityKinds.MolarMass, Set.of(Units.GM__PER__MOL)),
                 Arguments.of("m", QuantityKinds.Length, Set.of(Units.M)),
                 Arguments.of("/h", QuantityKinds.Frequency, Set.of(Units.PER__HR)),
                 Arguments.of("1/h", QuantityKinds.Frequency, Set.of(Units.PER__HR)),