WebApi.Hal version 8 - prerelease has pushed to Nuget

[panmanphil]

A new updated version of this library has been pushed to Nuget, version: 8.0.0-prerelease. Thanks to @LyndonGingerich who did all the work to bring the version forward to the current era and with fixed security vulnerabilites corrected. @marner2 also contributed with helpful comments.

After a short time, we will publish the final revision of the 8.0 release. We are aware of no breaking changes to the api.

[LyndonGingerich]

I cribbed a lot of his work, to be honest.

Should we update the release notes?

[panmanphil]

I'll add release notes and a missing README soon and then we are done