ci: setup carryforward for coverage

codecov.yml

@@ -0,0 +1,26 @@
+---
+flags:
+  analyzer:
+    paths:
+      - analyzer/
+    carryforward: true
+
+  api:
+    paths:
+      - api/
+    carryforward: true
+
+  api-client:
+    paths:
+      - api-client/
+    carryforward: true
+
+  playout:
+    paths:
+      - playout/
+    carryforward: true
+
+  shared:
+    paths:
+      - shared/
+    carryforward: true