Upgrade to scala 2.13

[fm3]

Let’s get rid of some technical debt. Also in preparation to the upgrade to play 2.9 (their migration guide is not yet released, but it says 2.12 support is discontinued)

• Upgrades to scala 2.13
• Upgrades some dependencies to newer version for compatibility
• Adapts to new syntax (added () in many places, new interface for mapping maps, no more Enumerators (had to re-write zip+nml i/o a bit), no more 'symbol literals, no more string concatenation with +, no more .zipped, new imports for java-to-scala conversions, )
• Imports swagger-play2 into the webknossos source
• Removes a few unused routes and classes (rather than adapt them to new scala version)

URL of deployed dev instance (used for testing):

• https://scala.webknossos.xyz

Steps to test:

• Browse around, annotate, download+reupload

TODOs:

• Library Dependencies
  • for build
  • for util
  • for datastore
    • webknossos-wrap Scala 2.13 webknossos-wrap#87
      • works with publishLocal
      • publish to maven
      • merge
      • use new version 1.1.23 in wk
    • swagger (https://github.com/swagger-api/swagger-play has been discontinued)
      • works with publishLocal
      • copy swagger-play into wk codebase
      • add license note for that package
      • test that new swagger.json is still working and re-generated python client passes CI
  • for tracingstore
  • for webknossos
• Adapt to breaking changes
  • No more Enumerators
  • asScala api change?
  • Slick Could not initialize class com.scalableminds.webknossos.schema.Tables$
• Adapt to scala deprecation warnings
• Test around
• Make CI happy
  • lint,format
  • adapt unit tests
  • snapshot tests (diff in user time tracking?)

Issues:

• fixes Upgrade to Scala 2.13 #7336

---

• Updated changelog
• Adapted wk-libs python client if relevant API parts change → Re-generate client with new swagger json webknossos-libs#944
• Considered common edge cases
  • test standalone datastore
• Needs datastore update after deployment