mice package in missing data module

Simplify calculations using `mice` package

Please have a look at below:

Within one function call we got the data for the first and second plot.

Adding this might simplify data transformations done in this module.

Please note special case of panel data (e.g. ADRS) where we want to have also count of missing in cols per patients in which we have `anyNA()` function. Thus, some transformations might be still needed.

Provenance:
```
Creator: pawelru
```