chore(framework): Move feature flags related resources and cleanup (#8297)

**What**
cleanup and move the feature flag related resources to manage them.

It also include some refactoring around loading and registering the flag as well as not relying on the `glob` package anymore plus some reorganization of the code itself

FIXES FRMW-2625

packages/modules/link-modules/package.json

@@ -32,6 +32,7 @@
     "@medusajs/types": "^1.11.16",
     "cross-env": "^5.2.1",
     "jest": "^29.7.0",
+    "medusa-test-utils": "^1.1.44",
     "pg-god": "^1.0.12",
     "rimraf": "^5.0.1",
     "ts-node": "^10.9.1",