Upgrade to Node 16

> Given that node 14 (and 16 for that matter) have been [deprecated](https://endoflife.date/nodejs), perhaps it might be a good time to start upgrading to a version >16 and resolve dependency issues for packages. WDYT? @CATcher-org/developers

_Originally posted by @vigneshsankariyer1234567890 in https://github.com/CATcher-org/CATcher/issues/1191#issuecomment-1586051114_

As mentioned by Vignesh, we should start upgrading to Node16+.

Let's upgrade to the next LTS version (Node 16) and resolve any dependency issues along the way.

With the upgrade from Node 14 to Node 16, we are also moving from npm6 to npm8

Potentially useful links:
- https://github.com/CATcher-org/CATcher/pull/964
- https://github.blog/2021-02-02-npm-7-is-now-generally-available/
- https://nodesource.com/blog/whats-new-in-npm-8/

To-do:
- [x] Bump failing libraries
- [x] Update workflows to use Node 16
- [ ] Update dev documents to recommend Node 16

Locate the developer documents referenced by the remaining checklist item and review their current Node.js setup instructions. Update them to recommend Node 16, including the npm 8 context noted in the issue. Done means the development documentation consistently recommends Node 16 and the existing upgrade checklist is complete.

Written by the indexing model from the issue text.