cMIS export: disable exporting data (inputs/outputs/workspace)

[elisabettai]

Planned changes

Since exporting (big) data is known to create issues, we can disable it for the moment (and remove it later). It doesn't seem to be required by cMIS, we will only need description of the inputs/outputs.

With the current implementation, I expect the folder storage to disappear.

This is a sub issue from ITISFoundation/osparc-issues#673.