MAGNOLIA-5975 brings support for transactional activation and versioning on multiple repositories. This name pattern <repositoryId>-<workspaceId> is used for for mgnlSystem and mgnlVersion workspaces, because it's needed to distinguish which mgnlSystem and mgnlVersion workspace belongs to which repository.

We should unify code for working with mgnlSystem and mgnlVersion workspaces. Get rid of usage of constants for those workspaces (info.magnolia.repository.RepositoryConstants#VERSION_STORE, info.magnolia.cms.beans.config.ContentRepository#VERSION_STORE, info.magnolia.cms.core.version.BaseVersionManager#VERSION_WORKSPACE, info.magnolia.repository.RepositoryConstants#SYSTEM, etc.) and introduce util methods for working with mgnlSystem and mgnlVersion workspaces (such a info.magnolia.jcr.util.VersionUtil#getVersionWorkspaceForNode)