[1.5.0-rc1] Visual Design: Continue button

[hqnnes]

Preview: https://xd.adobe.com/view/65742aa3-b407-427d-7329-956ae0fc6666-1345/
Specs: https://xd.adobe.com/spec/3ba570c1-ce1f-490c-61de-ba639e0f7f6a-4d94/

The continue button in “Add a VSP” (old name: “Add a Stakepool”) view has odd spacing and is a bit large. Also is now aligned to the right and cancel button to the left, according to the master alignment of the action buttons (#1820).