WIP: Integration of `WikiKB` into NEL benchmark

[rmitsch]

Description

Various changes to NEL benchmark in order to integrate WikiKB (and fix a few things along the way). Note: Do NOT merge at this point. This leverages experimental features of spacy and wikid.

Types of change

Enhancement.

Checklist

• [x] I confirm that I have the right to submit this contribution under the project's MIT license.
• [ ] I ran the tests, and all new and existing tests passed.
• [ ] My changes don't require a change to the documentation, or if they do, I've added all required information.