Set default aria-labels for trickle button

[kirsty-hames]

Subject of the issue

By default, there is no aria-label for Trickle buttons. For Buttons containing text this is fine as .trickle__btn-text is read instead.
For icon only trickle buttons (_hasIcon enabled and empty text), you need to set the appropriate ariaLabel, startAriaLabel and finalAriaLabel. From experience these are often missed and for most Adapt buttons we include aria-label defaults as standard e.g. question buttons.

Expected behaviour

Set aria-label defaults. Either pulling in the text startText and finalText so these are automatically populated when you amend the text properties (to save on amending multiple instances and to keep these consistent). Or to set defaults just copying the text startText and finalText text.

[kirsty-hames]

Either pulling in the text startText and finalText so these are automatically populated when you amend the text properties (to save on amending multiple instances and to keep these consistent).

On reflection, I think this approach could be utilised across Adapt. With AAT users in mind, having aria-label defaults that automatically inherit from the visually displayed text would be useful and we already have this approach with title and displayTitle in Adapt. They are linked by default but giving the flexibility to edit separately if required.

I'd be interested to hear thoughts from others.