Attempt at introducing codecov flags and carry them forward between test runs

.github/workflows/ui_tests.yml

@@ -52,3 +52,5 @@ jobs:
 
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v3
+        with:
+          flags: uitests

.github/workflows/unit_tests.yml

@@ -45,3 +45,5 @@ jobs:
       
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v3
+        with:
+          flags: unittests

codecov.yml

@@ -10,3 +10,12 @@ coverage:
 
 ignore:
   - "ElementX/Source/Generated"  # ignore the folder and all its contents
+
+flag_management:
+  default_rules:
+    carryforward: true
+    statuses:
+      - name_prefix: project-
+        type: project
+        target: auto
+        threshold: 1%