Rename `Hooks.tsx` file to what it contains

1. This does not contain JSX syntax so no need for ts_x_.
2. It default-exports a function, implying that we are not going
to export anything else, thus we can rename it to the hook that we
are exporting.

taker-frontend/src/App.tsx

@@ -37,7 +37,7 @@ import {
     WithdrawRequest,
 } from "./components/Types";
 import { Wallet, WalletInfoBar } from "./components/Wallet";
-import useLatestEvent from "./Hooks";
+import useLatestEvent from "./useLatestEvent";
 
 async function getMargin(payload: MarginRequestPayload): Promise<MarginResponse> {
     let res = await fetch(`/api/calculate/margin`, { method: "POST", body: JSON.stringify(payload) });