Adds ability to rearrange ballot items

[oemel09]

Description

In the BallotWizardFragment the ListView was changed to a RecyclerView.
The RecyclerView features drag and drop to reorder ballot items.

• When adding a new item the list will scroll to the bottom to make the new item visible
• When scrolling through the list and opening the keyboard afterwards, the list will scroll to the last visible item

Checklist

• I signed the Contributor License Agreement
• All changes in this pull request were created by me, I own the full copyright
  for all these changes

[threema-danilo]

Thanks @oemel09 for your contribution! We have applied your changes internally, they should become part of the next release.