Add an E2E test that SQL connection string login skips the Portal Backend

Nothing asserted the defining behavior of the direct login path, so reverting the short-circuit in connectWithConnectionString would have gone unnoticed. The listener filters on the connectionstring route so it covers both generatetoken and accessinputmetadata, and leaves the account restriction check alone since that still runs for every API.

src/HostedExplorer.tsx

@@ -36,7 +36,7 @@ const App: React.FunctionComponent = () => {
   // For handling encrypted portal tokens sent via query paramter
   const params = new URLSearchParams(window.location.search);
   const [encryptedToken, setEncryptedToken] = React.useState<string>(params && params.get("key"));
-  // Encrypted token logins resolve the account metadata through the Portal Backend, while SQL/Tables/Gremlin
+  // Encrypted token logins resolve the account metadata through the Portal Backend, while SQL/Table/Gremlin
   // connection-string logins derive it client-side, so both paths write to the same value.
   const [accountMetadata, setAccountMetadata] = React.useState<AccessInputMetadata>();