WIP add sbt support

[oalyman]

adds sbt / scala support

WIP ...

[michaelsauter]

Cool, tests pass!

Is there any way to make this run faster?

--- PASS: TestTaskODSBuildSbt (299.75s)
    --- PASS: TestTaskODSBuildSbt/task_should_build_sbt_sample_app (296.78s)

vs. e.g.

--- PASS: TestTaskODSBuildGo (239.99s)
    --- PASS: TestTaskODSBuildGo/build_go_app (79.79s)
    --- PASS: TestTaskODSBuildGo/build_go_app_with_build_caching (62.16s)
    --- PASS: TestTaskODSBuildGo/build_go_app_in_subdirectory (35.11s)
    --- PASS: TestTaskODSBuildGo/fail_linting_go_app_and_generate_lint_report (7.97s)
    --- PASS: TestTaskODSBuildGo/build_go_app_with_pre-test_script (18.09s)
    --- PASS: TestTaskODSBuildGo/build_go_app_in_PR (35.18s)

[michaelsauter]

Closing as a consequence of #722. Now build tasks are in their separate repos, with separate lifecycles and test suites. If you want to contribute a Scala task, just copy e.g. ods-pipeline-gradle, then adjust it to the Scala content in this PR.