Upgrade Material UI library from v4 to v5

Problem/Motivation

Anu LMS uses Material UI library v4 (https://v4.mui.com) which is being deprecated in favour of Material UI version 5 (https://mui.com). See https://mui.com/versions/ for all versions and milestones.

Looks like v6 has not yet started (as of 5th of Feb 2023), therefore migrating to v5 is a reasonable version to migrate to.

Proposed resolution

Upgrade all components used for Material UI v4 to Material UI v5 following to the migration guide: https://mui.com/material-ui/migration/migration-v4/

Remaining tasks

- TBD