Update all dependencies to latest

Enzyme kept React at v16 because of the still missing v17 adapter, and @hot-loader/react-dom kept React at 17.0.1 because the 17.0.2 isn't released yet. With these dependencies gone, all dependencies can now be updated to latest.

NOTE: webpack-dev-server is incorrectly reported as outdated by npm due to incorrect tagging of the 4.0.0-beta.N releases as latest.

Author: Oblosys