Model: pass relation name to database #142

Also fix test that is asserting query parameters. This also nicely
verifies that passing the name works.

Author: greenrobot-team

objectbox/lib/src/native/model.dart

@@ -142,6 +142,14 @@ class Model {
   void addRelation(ModelRelation rel) {
     _check(C.model_relation(
         _cModel, rel.id.id, rel.id.uid, rel.targetId.id, rel.targetId.uid));
+
+    final name = rel.name.toNativeUtf8();
+    try {
+      _check(C.model_relation_name(_cModel, name.cast()));
+    } finally {
+      calloc.free(name);
+    }
+
     if (rel.externalType != null) {
       _check(C.model_relation_external_type(_cModel, rel.externalType!));
     }

objectbox_test/test/query_test.dart

@@ -976,7 +976,7 @@ void main() {
         [
           'tString == "foo"',
           '| Link RelatedEntityB via relBId with conditions: tString == "bar"',
-          '| Link RelatedEntityA via standalone Relation 1 (from entity 1 to 4) with conditions: tInt == 11',
+          '| Link RelatedEntityA via standalone Relation 1 (relManyA) (from entity 1 to 4) with conditions: tInt == 11',
         ].join('\n'));
   });