file drop support

- Add a folder where you can drop Zip files which will then be
  extracted on the fly and ingsted.
- CsvReaderSettings now contain TagMatcher that are applied to the
  first line and can be used to extract additional tags.
- Update to jdk 16 so that we can have records.

pdb-api/src/main/java/org/lucares/pdb/api/Tags.java

@@ -1,7 +1,9 @@
 package org.lucares.pdb.api;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.TreeSet;
@@ -26,12 +28,13 @@ public class Tags implements Comparable<Tags> {
         tags = new ArrayList<>();
     }
 
-    public Tags(final List<Tag> tags) {
-        Collections.sort(tags, TagByKeyAndValueComparator.INSTANCE);
-        this.tags = tags;
+    public Tags(final Collection<Tag> tags) {
+        final List<Tag> t = new ArrayList<>(tags);
+        Collections.sort(t, TagByKeyAndValueComparator.INSTANCE);
+        this.tags = t;
     }
 
-    public static Tags create(final List<Tag> tags) {
+    public static Tags create(final Collection<Tag> tags) {
 
         return new Tags(tags);
     }
@@ -139,6 +142,20 @@ public class Tags implements Comparable<Tags> {
         return 0;
     }
 
+    /**
+     * Creates new {@link Tags} with the tags from {@code this} and the tags from
+     * {@code tags}, possibly overwriting tags of {@code this}.
+     * 
+     * @param tags the new tags
+     * @return {@link Tags}
+     */
+    public Tags add(final Tags tags) {
+        final Set<Tag> result = new HashSet<>();
+        result.addAll(this.tags);
+        result.addAll(tags.toTags());
+        return Tags.create(result);
+    }
+
     public String getValue(final String key) {
         final Tag needle = new Tag(STRING_COMPRESSOR.put(key), 0);