Add icon to field errors

[adamculpepper]

Bootstrap4's method:

border-color: #dc3545;
padding-right: calc(1.5em + 0.75rem);
background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='none' stroke='%23dc3545' viewBox='0 0 12 12'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23dc3545' stroke='none'/%3e%3c/svg%3e");
background-repeat: no-repeat;
background-position: right calc(0.375em + 0.1875rem) center;
background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);