Added the codecov-based reporting.

Author: martysai

.github/workflows/ci.yml

@@ -37,5 +37,7 @@ jobs:
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: ./coverage.xml
+          flags: unittests
+          name: ci-coverage
           fail_ci_if_error: false
           verbose: true

codecov.yml

@@ -0,0 +1,11 @@
+comment:
+  layout: "reach,diff,flags,tree"
+  behavior: default
+  require_changes: false
+  require_base: no
+  require_head: yes
+
+# Optional: configure thresholds or ignore patterns below
+# coverage:
+#   precision: 2
+#   round: down