Extend dvc remove to work with remotes

Hi guys, thank you for the great tool!

We'd like to ask you for some tweaks in the process of removing data from DVC remotes.

Here is our use case: we generate some features from the raw data and store them in our DVC remotes. Unfortunately, the amount of the features exceeds our storage space (moreover, the generation process is not fixed and we experiment with it constantly, so sometimes we have multiple versions of features generated from the same source data). So, we need a way to periodically remove data from the remotes. Current one, using dvc gc together with setting and removing git tags, seems to be too fragile for our use case: it relies on precise tagging and requires careful manipulation of the tags. Additionally, it works mostly with one particular instance of git project, but we usually have several ones for different team members. Moreover, we are using the same data from several projects (we have one project working as data registry and several consumer projects), so running dvc gc without accidentally deleting some data from another project becomes quite non-trivial. Can we have the extended functionality of dvc remove instead? Something like dvc remove --remote path/to/data to remove the specified file not only from the workspace, but also from cache and remote. That way we can specify exactly what data should be removed.

Additionally it would be nice to have a way to remove only the data generated by a dvc pipeline from remote, but leave the pipeline itself untouched, so we can go back to it and regenerate data using dvc repro, but it may be a different issue.

Start by examining the existing dvc remove and dvc gc entry points, then compare how remote data is selected and deleted. Use the requested dvc remove --remote path/to/data behavior as the target, while considering the separate pipeline-data case involving dvc repro; done means the intended remote deletion scope is defined and covered by tests.