[POC] NEXUS-6102: Ditch mimeUtil2, use Tika

Dropped MimeUtil2 (dead) library, using Apache Tika instead.
This is just a POC, it has many drawbacks for Nx users. MimeUtil2 consumed legacy mime magic files of hosting OS and the OpenDesktop ones in binary form. Apache Tika supports only the OpenDesktop XML mime databases (no intersection among the two!). Still, question is, why did we need a full host OS magic database at all....

Issue
https://issues.sonatype.org/browse/NEXUS-6102

CI
TBD