feat(openpipeline-v2) enable pipeline groups and add docs#847

Kirdock wants to merge 4 commits intotest/openpipeline-v2/pipeline-groups-e2edynatrace-oss/terraform-provider-dynatrace:test/openpipeline-v2/pipeline-groups-e2efrom

feat/openpipeline-v2-pipeline-groups/wire-up-and-docdynatrace-oss/terraform-provider-dynatrace:feat/openpipeline-v2-pipeline-groups/wire-up-and-docCopy head branch name to clipboard