Remove test-related code, data and unnecessary embedded JARs from platform bundles
- org.simantics.databoard/testcases shouldn't be included in the binary build
- org.simantics.graph contains testing-related TG files in the src directory, which are several MB in size
- org.simantics.spreadsheet.graph contains apache commons math 3.6.1 which already comes into the platform as a third-party dependency through P2 repositories. It takes around 2 MB.