- drop support for tag SHA as in most cases this information is not available at the moment

- introduce new testcase to verify `DAYS_SINCE` calculation
- fix wrong log messages using the `TagInfo` object instead the name
- add additional log messages

configs_test/configuration_approvers.json

@@ -1,4 +1,4 @@
 {
-    "template": "${{CHANGELOG}}",
+    "template": "${{CHANGELOG}}\n\n${{DAYS_SINCE}}",
     "pr_template": "- ${{TITLE}} -- (#${{NUMBER}}) [${{STATUS}}] ${{REVIEWERS}} --- ${{APPROVERS}}"
 }