docs: Correcting errors in methods and types

[markgoho]

Checklist

• Issue number for this PR: 4.0.0 Docs refer to incorrect afAuth.subscribe method #960
• Docs included?: yes, this is a docs change
• Test units included?: no
• e2e tests included?: no
• In a clean directory, npm install, npm run build, and npm test run successfully? yes

Description

There were numerous errors (leftovers from < 4.0.0-rc.0) that were causing implementations of the sample code to fail compiling and/or produced Typescript errors.

These changes should bring the code up to current release compatibility.

Code sample

n/a