Resolve "Relevance Ranking in Metadata"

Required MRs to be merged before

• codeabilitysharingpluginapi!2 (merged)
• !217 (merged)
• codeabilitysharingpluginapi!3 (merged)

Related to #439 (closed)

src/main/java/at/ac/uibk/gitsearch/repository/search/MetaDataRepository.java

@@ -311,7 +311,7 @@ public class MetaDataRepository {
                         }
                     });
 
-                reloadedCachedCompletions.values().forEach(c -> simplify(c));
+                reloadedCachedCompletions.values().forEach(this::simplify);
                 cachedCompletions = reloadedCachedCompletions;
             } catch (co.elastic.clients.elasticsearch._types.ElasticsearchException | ElasticsearchException | ConnectException ex) {
                 // this may happen mainly during testing, when
@@ -336,7 +336,7 @@ public class MetaDataRepository {
         entries.forEach((lowerCaseValue, upperCaseValues) -> {
             final Optional<Entry<String, Integer>> max = upperCaseValues.entrySet().stream().max((e1, e2) -> e1.getValue() - e2.getValue());
             max.ifPresent(maxEntry -> {
-                int sum = upperCaseValues.entrySet().stream().mapToInt(o -> o.getValue()).sum();
+                int sum = upperCaseValues.entrySet().stream().mapToInt(Entry::getValue).sum();
                 entries.put(lowerCaseValue, Collections.singletonMap(maxEntry.getKey(), sum));
             });
         });