Add faster nquads parser and chunked k-way merge architecture

[hmottestad]

Issue resolved (if any): #

Description of this pull request:

---

Please check all the lines before posting the pull request:

• I've created tests for all my changes
• My pull request isn't fixing or changing multiple unlinked elements (please create one pull request for each element)
• I've applied the code formatter (mvn formatter:format on the backend, npm run format on the frontend) before posting my pull request, mvn formatter:validate to validate the formatting on the backend, npm run validate on the frontend
• All my commits have relevant names
• I've squashed my commits (if necessary)

[hmottestad]

@D063520 @ate47 Could you start looking at this PR?

I know it says 231 files modified, but that includes 165 nquad and ntriple test files from W3C.

[ate47]

I didn't look everything in detail, but it seems fine. I had a question about a test