module-info.java, 2nd attempt

[wadoon]

Second run for module-info in KeY after the drop of ST4. Builds-upon #3621, should merged afterwards.

This pull request adds module support in KeY by adding module-info.java and doing the necessary stuff. There are three main issues with modules in KeY:

• clashing Java packages (packages are sealed)
  (solved by renaming some packages)

• Docking Frames is not-modularized
  (Baked a new version, with renamed packages. **This version is on central snapshot repo, and should then be deployed to Maven central)

• Caching extension in wrong service file

Additional:

• Removal of ANTLR2+3 from KeY.

Hint:

• Isabelle translation added a Scala library, which breaks the Java module convention, but it seems not to break the JVM module system (invalid module name).

Type of pull request

• Refactoring (behaviour should not change or only minimally change)

[Drodt]

Is this really ready for review?

[wadoon]

Is this really ready for review?

A review should wait for #3621. This PR builds upon it (removal of ST4).