Admin enterprise users - show inline error style consistent with product list

[mariocarabotta]

Description

Currently the style for the inline error shown in the Add manager dialog is inconsistent with the latest one we have introduced in the product list.

Expected Behavior

Should look like product list, color, size and icon

Actual Behaviour

has different style

Steps to Reproduce

1. Go to /admin/enterprises/ and select one
2. Go to users
3. Add an existing user or add an invalid email address

Severity

bug-s5: we can live with it, only a few users impacted

[mariocarabotta]

relates to #9491
#13895