feat: add Reachability Center and Why Drawer components with tests

- Implemented ReachabilityCenterComponent for displaying asset reachability status with summary and filtering options.
- Added ReachabilityWhyDrawerComponent to show detailed reachability evidence and call paths.
- Created unit tests for both components to ensure functionality and correctness.
- Updated accessibility test results for the new components.

src/Web/StellaOps.Web/test-results/.last-run.json

@@ -1,4 +1,4 @@
 {
-  "status": "interrupted",
+  "status": "passed",
   "failedTests": []
 }

src/Web/StellaOps.Web/test-results/a11y-_.json

@@ -0,0 +1,4 @@
+{
+  "url": "http://127.0.0.1:4400/console/profile",
+  "violations": []
+}

src/Web/StellaOps.Web/test-results/a11y-_graph.json

@@ -0,0 +1,4 @@
+{
+  "url": "http://127.0.0.1:4400/graph",
+  "violations": []
+}