Refactor codebase, introduce relaymode package, update constants and improve consistency

- Refactor constant definitions and organization
- Clean up package level variables and functions
- Introduce new `relaymode` and `apitype` packages for constant definitions
- Refactor and simplify code in several packages including `openai`, `relay/channel/baidu`, `relay/util`, `relay/controller`, `relay/channeltype`
- Add helper functions in `relay/channeltype` package to convert channel type constants to corresponding API type constants
- Remove deprecated functions such as `ResponseText2Usage` from `relay/channel/openai/helper.go`
- Modify code in `relay/util/validation.go` and related files to use new `validator.ValidateTextRequest` function
- Rename `util` package to `relaymode` and update related imports in several packages

web/default/src/App.js

@@ -24,6 +24,7 @@ import EditRedemption from './pages/Redemption/EditRedemption';
 import TopUp from './pages/TopUp';
 import Log from './pages/Log';
 import Chat from './pages/Chat';
+import LarkOAuth from './components/LarkOAuth';
 
 const Home = lazy(() => import('./pages/Home'));
 const About = lazy(() => import('./pages/About'));
@@ -239,6 +240,14 @@ function App() {
           </Suspense>
         }
       />
+      <Route
+        path='/oauth/lark'
+        element={
+          <Suspense fallback={<Loading></Loading>}>
+            <LarkOAuth />
+          </Suspense>
+        }
+      />
       <Route
         path='/setting'
         element={