MAVSDK tests: Enable coverage testing

This enables minimal coverage testing for multicopters.

codecov.yml

@@ -0,0 +1,30 @@
+codecov:
+  require_ci_to_pass: yes
+
+coverage:
+  precision: 2
+  round: down
+  range: "70...100"
+
+  status:
+    project: yes
+    patch: yes
+    changes: no
+
+parsers:
+  gcov:
+    branch_detection:
+      conditional: yes
+      loop: yes
+      method: no
+      macro: no
+
+comment:
+  layout: "reach,diff,flags,tree"
+  behavior: default
+  require_changes: no
+
+# fixes:
+#     - "platforms/::./platforms/"
+#     - "src/::./src/"
+#     - "mavlink/::./mavlink/"