Generate a BIDS demo dataset

Based on BIDS example dataset from Charite, generate a new sintetic dataset to be used in unit-tests, but also for publishing it on Zenodo with tvb-data.

The published Zenodo data will be useful for end-users as example of BIDS dataset good for TVB.

The new demo dataset should be as small as possible, to still be usefull.

For example one (max 2 TS datasets are expected, of relatively short length). One Connectivity...