[Query Copilot V2] Restructure code for V2 of copilot (#1577)

* Initial folder and code restructure

* Add snapshots

* Remove flag for local testing

* Remove unnecessary code

* Fix snapshot

* Update tests

src/Explorer/QueryCopilot/V2/Header/Header.tsx

@@ -0,0 +1,39 @@
+import { IconButton, Image, Stack, Text } from "@fluentui/react";
+import { useQueryCopilot } from "hooks/useQueryCopilot";
+import React from "react";
+import CopilotIcon from "../../../../../images/CopilotSidebarLogo.svg";
+
+export const Header: React.FC = (): JSX.Element => {
+  const { setShowCopilotSidebar } = useQueryCopilot();
+
+  return (
+    <Stack
+      style={{ margin: "15px 0px 0px 0px", padding: "5px", display: "flex", justifyContent: "space-between" }}
+      horizontal
+      verticalAlign="center"
+    >
+      <Stack horizontal verticalAlign="center">
+        <Image src={CopilotIcon} />
+        <Text style={{ marginLeft: "5px", fontWeight: "bold" }}>Copilot</Text>
+        <Text
+          style={{
+            background: "#f0f0f0",
+            fontSize: "10px",
+            padding: "2px 4px",
+            marginLeft: "5px",
+            borderRadius: "8px",
+          }}
+        >
+          Preview
+        </Text>
+      </Stack>
+      <IconButton
+        onClick={() => setShowCopilotSidebar(false)}
+        iconProps={{ iconName: "Cancel" }}
+        title="Exit"
+        ariaLabel="Exit"
+        style={{ color: "#424242", verticalAlign: "middle" }}
+      />
+    </Stack>
+  );
+};