Fix add and remove a public key / share buttons

This relates to the backup and recover pages.

• The + icon is blurred, and the icons are smaller so it needs to be exported with the whole white area https://www.figma.com/file/FEStqomP7gjtELknSyPcCL?node-id=131:1645#326023430  
• The text next to the + is missing. 'Add one more'
• And once you have added it, you should be able to remove it. Which is my mistake as it was in previous versions. https://www.figma.com/file/FEStqomP7gjtELknSyPcCL?node-id=1107:2036#326025007