Better MNE-Integration: live conversion between our and their data classes

[dfsp-spirit]

We encourage use of both Syncopy and MNE, and do not want to reinvent the wheel by building complex features that are already available in MNE. To make working with both software systems easier, it would be nice to make it easier to convert data between MNE and Syncopy.

Do you have a solution in mind? Please elaborate
Would be good to add some wrapper methods for easy conversion between our dataclasses (like AnalogData) and the MNE data classes (Raw, Epcohed, ...).

Additional context
Some examples where Syncopy users may want to switch to MNE is for stuff like ICA and source localization.

[tensionhead]

pynwb might just do this for us, as MNE also supports the NWB format.. see #508