Show transaction size in human readable format #51
Description
On the signing page, the call data is shown in 1e18, This makes it extremely hard to verify actual transaction sizes.
In this example, without actually counting the zeroes, it's hard to see if it is 0.2 ZCHF, 2 ZCHF or even 2000 ZCHF.
Adding a human readable number format would alleviate this potential security problem.
