feat: Add plugin slot for login page

This change adds a plugin slot for the login page allowing it to be customised.

Since there was a dependency conflict between frontend-plugin-framework and the react-hooks testing package, the react-hooks testing package has been removed and a replaced with a simple mechanism for testing hooks.

Since this touched the Login Page those have also been refactored to move away from redux connect.

Author: xitij2000

package-lock.json

@@ -36,6 +36,7 @@
     "@fortawesome/free-brands-svg-icons": "6.7.2",
     "@fortawesome/free-solid-svg-icons": "6.7.2",
     "@fortawesome/react-fontawesome": "0.2.6",
+    "@openedx/frontend-plugin-framework": "^1.7.0",
     "@openedx/paragon": "^23.4.2",
     "@optimizely/react-sdk": "^2.9.1",
     "@redux-devtools/extension": "3.3.0",