feat: Adjust global hooks to work with both knex and objection

packages/backend/src/types/global.d.ts

@@ -1,8 +1,11 @@
 import { Knex } from 'knex';
+import { Transaction } from 'objection';
 
 declare global {
   declare namespace globalThis {
     // eslint-disable-next-line no-var
-    var knex: Knex;
+    var knexInstance: Knex;
+    // eslint-disable-next-line no-var
+    var knex: Transaction;
   }
 }