externalize dependency on git lfs

[Panaetius]

Similar to #2253 we should have an interface&implementation combo for large file storages, so we could ideally swap out git lfs for e.g. S3 buckets.

One issue here is that we depend on some git lfs specific implementation details, like git lfs migrate which might not make sense in the context of most providers, so we might not want that on the interface, but only on the implementation, and have the cli code depend on the implementation directly for those commands (with the business logic not knowing about them)