Use font with equally wide number characters for balance label in Payment Request View #642

Description

Currently used WorkSans does not have equally wide number characters, which makes it harder to create input field with adjustable font size. A less performant or less maintainable solution is thus required.

Steps to reproduce the behavior

Visit Payment Request Screen

Expected behavior

A traditional font, where every number character takes exactly the same width (OpenSans), should be used. A downside of such solution is that it will usually take more horizontal space for the same string of numbers.

Actual behavior

When you calculate font size based on number of characters and available width, you are left with some white space.

Needed to resolve issue No.

#294