Remove toolkit button sass

[andysellick]

Removes the last dependency on govuk_frontend_toolkit, for button styles. Most of the buttons in finder-frontend had already been converted to use the button component already.

This change involves a visual change on the subscription page. This button is now using the button component:

Before

After

This change unfortunately required a custom wrapper on the text above in order to provide margin bottom. Hopefully this will be made obsolete at some point if the govspeak component is given margin bottom.

Note: in replacing this button I noticed that the submit_tag rails command adds a data attribute of data-disable-with to the outputted HTML. I don't know if this is important but to be safe I've configured the button component to include this attribute.

Example links:

• https://finder-frontend-pr-1016.herokuapp.com/search/news-and-communications/email-signup
• https://finder-frontend-pr-1016.herokuapp.com/search/news-and-communications/ (turn off JS)

I don't think there's any other buttons, but happy to be proved wrong.

[sihugh]

Looks great apart from the unnecessary disable-with bit. 👍

I concur that I think the buttons you found are the only ones.