refactor: Speed up Config fetching and Setup Config Groundwork 👷🚧 (#1297)

* refactor: move endpoint services to own directory

* refactor: make endpointconfig handling more concise, separate logic, and cache result for subsequent serving

* refactor: ModelController gets same treatment as EndpointController, draft OverrideController

* wip: flesh out override controller more to return real value

* refactor: client/api changes in anticipation of override

client/src/data-provider/index.ts

@@ -1 +1,2 @@
 export * from './mutations';
+export * from './queries';

client/src/data-provider/queries.ts

@@ -0,0 +1,17 @@
+import { UseQueryOptions, useQuery, QueryObserverResult } from '@tanstack/react-query';
+import { QueryKeys, dataService } from 'librechat-data-provider';
+
+export const useGetEndpointsConfigOverride = <TData = unknown | boolean>(
+  config?: UseQueryOptions<unknown | boolean, unknown, TData>,
+): QueryObserverResult<TData> => {
+  return useQuery<unknown | boolean, unknown, TData>(
+    [QueryKeys.endpointsConfigOverride],
+    () => dataService.getEndpointsConfigOverride(),
+    {
+      refetchOnWindowFocus: false,
+      refetchOnReconnect: false,
+      refetchOnMount: false,
+      ...config,
+    },
+  );
+};