touch feedback should always be applied to buttons

Touch feedback (slight background change) works on all top-level ~~components~~ labels. However, ~~nested~~ Buttons can also have actions attached, therefore should also have the touch feedback applied.

Additionally, you may consider adding the property: `touchFeedback: true|false` for more flexibility.

Start by locating where touch feedback is applied to top-level labels and where nested Buttons handle actions. Done means Buttons with attached actions receive the same slight background change; consider whether the optional touchFeedback property should also be included.

Written by the indexing model from the issue text.