Merge branch...

Merge branch 'amiranda/45-refactor-library-rpc-implementation-of-admire-transfer_dataset' into 'main'

Resolve "Refactor library RPC implementation of `admire::transfer_dataset`"

This MR reimplements the `ADM_transfer_dataset` RPC with complex data types from the ADMIRE API.

It also renames the C API function to `ADM_transfer_datasets` (and similarly for the CXX API) since it is now possible to define the transfer for more than one dataset in the same call.

Closes #45

See merge request !30