Field validation texts are not translated

[tomasMizera]

Description
Validation texts from fieldvalidator.h's namespace are not translated, they are always in English. This is because the strings are static and initialized before translator is instantiated.

Environment
Production

Steps to reproduce

1. Set the app to any language that is fully translated and is not English
2. Open a form where you have a field with a set constraint (e.g. not null)

Actual results

1. Field will show "Field must not be empty" in English

Expected results

1. Field should show "Field must not be empty" translated in the target language