UI: Create invoice copy

[swedishfrenchpress]

We received the following feedback from a user regarding the creating invoice copy.
"Hosever this part was a bit unclear. I wasnt sure if they meant sats or full bitcoins or something else."

Let's review this think about ways to make this clearer.

[Egge21M]

This is how I implement it on Current.

To native keyboard or not to is personal preference, but by putting the currency behind the input field it gets clear what you are supposed to enter.

[KKA11010]

Makes sense to show Sat. there :) also was thinking about showing the BTC format right under it, like in zeus? WDYM? 😏