[Feature Request] Usability of working with data

Easier ways to access individual cycles and steps


For example, get the first cycle as a df:

```
datapath.raw_data.cycles[1]
```

Or, get the 5th step of the first cycle
```
datapath.raw_data.cycles[1].steps[5]
```


Please leave suggestions if you have ideas for how else usability of datapath can be improved
