[usability] [UI] price setting with automated decimal point

[stheid]

many modern apps like e.g. Paypal have adapted the userinterfaces to typing values like it is common in POS systems.

5.36€ is achieved by pressing '5' '3' '6' instead of '5' ',' '3' '6', basically shifting the digits from left to right.

This is obviously a design choice that might have haters and lovers, so its up to the maintainers to decide. I personally however see more and more apps using this input method and think its in general much faster for the amount of values that are typically typed in grocy. In particularly i noticed this today when shopping where i had to add a lot of numbers right after the other