Allow for inconsistent streams across experiments

The `read_openephys` function requires streams to be consistents across experiments (this can happen if probes get connected/disconnected across experiments).
If this is not the case, it will throw an error as:
```
Inconsistent continuous streams across blocks (experiments)! Streams for different experiments in the same folder must be the same. You can load a subset of experiments with the 'experiment_names' argument: ['experiment1', 'experiment2', 'experiment3', 'experiment4']
```
Since downstream we process streams separately, we can look for grups of consistent streams (at least looking for a single split) and parse the two sets of consistent streams separately.