- expand configuration specification by offering sorting by alternative properties -> title instead of mergedAt.

- add more testcases to cover the new sort orders
  - FIX https://github.com/mikepenz/release-changelog-builder-action/issues/757

configs_test/configuration_desc.json

@@ -1,5 +1,8 @@
 {
-    "sort": "DESC",
+    "sort": {
+        "order": "DESC",
+        "on_property": "mergedAt"
+    },
     "pr_template": "${{NUMBER}}",
     "max_pull_requests": 1000,
     "max_back_track_time_days": 1000

configs_test/configuration_sort_title_asc.json

@@ -0,0 +1,9 @@
+{
+    "sort": {
+        "order": "ASC",
+        "on_property": "title"
+    },
+    "pr_template": "${{TITLE}}",
+    "max_pull_requests": 1000,
+    "max_back_track_time_days": 1000
+}

configs_test/configuration_sort_title_desc.json

@@ -0,0 +1,9 @@
+{
+    "sort": {
+        "order": "DESC",
+        "on_property": "title"
+    },
+    "pr_template": "${{TITLE}}",
+    "max_pull_requests": 1000,
+    "max_back_track_time_days": 1000
+}