Add raw GVL evidence storage and restore evidence purge UI

src/background.js

@@ -672,8 +672,23 @@ async function fetchOfficialGvlJson() {
     throw error;
   }
 
+  const rawBody = await response.text();
+  const fetchedAt = new Date().toISOString();
+  const contentType = response.headers.get("Content-Type");
+  const rawGvlSha256 = await VendorGetGvlService.calculateRawGvlSha256(rawBody);
+  const db = await openVendorGetDb();
+
+  await VendorGetGvlService.storeGvlRawEvidenceIfNew(db, {
+    rawGvlSha256,
+    sourceUrl: OFFICIAL_IAB_GVL_URL,
+    fetchedAt,
+    httpStatus: response.status,
+    contentType,
+    rawBody
+  });
+
   return {
-    rawJson: await response.json(),
+    rawJson: JSON.parse(rawBody),
     responseStatus: response.status
   };
 }