Allow error summary config set via data attributes to be passed when initialising the component in JavaScript

[36degrees]

What

The error summary component currently uses a data-disable-auto-focus data attribute to prevent the component from taking focus on page load. (This is mostly designed to be used when the component is displayed in a different context, e.g. in the Design System itself)

Update the component so that the config can also be passed as an object when initialising the component in JavaScript.

As per #1708 (comment), any config passed via data attributes takes precedence over config passed when initialising a component.

Why

This aligns the general concept of 'component config' with the approach we're using for internationalisation.

Who needs to work on this

Developers

Who needs to review this

Developers

Done when

• The 'disable auto focus' functionality can be provided when instantiating an ErrorSummary object
• The 'disable auto focus' functionality can be provided when instantiating an ErrorSummary object using initAll
• If a data-disable-auto-focus data attribute is present on the $module HTML element it overrides any config set via initialisation
• Tests to cover the above