Allow disabling versions on upload and add CreateFileVersion

[diocas]

The CS3APIs implementation should allow disabling the creation of a version when saving a file.
At the same time, it should be possible to manually create a version, so a new method needs to be added.

This will be useful for apps that want to do auto save, which should not overwrite other versions (which might happen if a limited number of versions is allowed).

The storage implementation should be able to handle these cases. EOS already does: https://its.cern.ch/jira/browse/EOS-4503

[diocas]

@glpatcern @labkode we reached a point where this is really necessary (@piotrWichlinskiSoftwaremind is starting the implementation for Jupyter)

[labkode]

@diocas the creation of versions on upload is driver specific, so any change needs to happen on the driver. What driver is being used in the integration system? EOS?

For the CreateVersion, can you create an PR in the CS3APIs with the desired behaviour?

[glpatcern]

@diocas the creation of versions on upload is driver specific, so any change needs to happen on the driver. What driver is being used in the integration system? EOS?

Yet it does make sense to have e.g. a flag on InitiateUploadRequest in order to enable/disable versioning, which could (or could not) be honored by the storage driver.