[REFACTORAPI] Refactors IWorkspace interface

Adds getProject and getLocation methods, removes intellij.core duplicates.

Change-Id: If6037905433eefca973e03b95312c5d7088aeec2
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1961
Tested-by: Jenkins CI
Reviewed-by: Damla Durmaz <ddurmaz88@gmail.com>
Reviewed-by: Holger Schmeisky <google@schmeisky.com>