Refactor supabase client file

Refactor the supabase client file into smaller modules.

src/lib/supabase/index.ts

@@ -2,11 +2,18 @@
 import { supabase, isValidUrl } from './client';
 import { testSupabaseConnection } from './tests';
 import { createRequiredTables, checkTablesStatus } from './setup';
+import { customFetch } from './customFetch';
+import { modifyStorageApiRequest, getStorageApiHeaders } from './storageUtils';
+import { testConnection } from './connectionTest';
 
 export {
   supabase,
   isValidUrl,
   testSupabaseConnection,
   createRequiredTables,
-  checkTablesStatus
+  checkTablesStatus,
+  customFetch,
+  modifyStorageApiRequest,
+  getStorageApiHeaders,
+  testConnection
 };