Validation messages escape HTML incorrectly

Problem/Motivation

Currently it's possible to add html to the label of a component (For example
<strong> or a <span>
with a class etc.)

However if validation fails server side and the field name is output into the messages area then the html tags are escaped and display on screen.

Steps to reproduce

Create a new form using the below. (One required element with html in the label)
Via Settings -> Form set
Disable client-side validation and Disable inline form errors

Save.

Submit form without selecting anything.

_strong_title_strong_here:
  '#type': checkbox
  '#title': '<strong>Title</strong> here'
  '#equal_stepwise_validate': 0
  '#equal_components': {  }
  '#compare': 0
  '#compare_components': ''
  '#compare_components_operator': ''
  '#compare_components_custom_error': ''
  '#some_of_several': 0
  '#some_of_several_components': {  }
  '#some_of_several_components_completed': ''
  '#some_of_several_final_validation': 0
  '#required': true