Split button added

In order to use split feature CreateNewTransaction
had to be changed: It is not changing the guid property of the given
transaction.

this way while splitting, we can insert new item to the list without
reading all items from db, while keeping the guid data accurate.

Spliter separator added with option to manually set the amount, without
using the slider.

The import-stage considered and while in import stage splitting not
creating new transaction on db