Refactor: Extract root components architecture with comprehensive tests

src/RootComponents/LoadingExplorer.tsx

@@ -0,0 +1,36 @@
+import { makeStyles } from "@fluentui/react-components";
+import React from "react";
+import hdeConnectImage from "../../images/HdeConnectCosmosDB.svg";
+
+const useStyles = makeStyles({
+  root: {
+    height: "100vh",
+    width: "100vw",
+    backgroundColor: "var(--colorNeutralBackground1)",
+    color: "var(--colorNeutralForeground1)",
+  },
+});
+
+function LoadingExplorer(): JSX.Element {
+  const styles = useStyles();
+
+  return (
+    <div className={styles.root}>
+      <div className="splashLoaderContainer">
+        <div className="splashLoaderContentContainer">
+          <p className="connectExplorerContent">
+            <img src={hdeConnectImage} alt="Azure Cosmos DB" />
+          </p>
+          <p className="splashLoaderTitle" id="explorerLoadingStatusTitle">
+            Welcome to Azure Cosmos DB
+          </p>
+          <p className="splashLoaderText" id="explorerLoadingStatusText" role="alert">
+            Connecting...
+          </p>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+export default LoadingExplorer;