[Neue] Buttons (#5406)

* Re-align button sizing

(cherry picked from commit bcec243bb59dfe468313d98ba61f464d9750feec)

* Use large, small, tiny

(cherry picked from commit 1dc333c2993ab7f2e0ac750c0670dcec9a7069d0)

* Tweaks

src/components/Prompt.tsx

@@ -120,7 +120,7 @@ export function Cancel({
     <Button
       variant="solid"
       color="secondary"
-      size={gtMobile ? 'small' : 'medium'}
+      size={gtMobile ? 'small' : 'large'}
       label={cta || _(msg`Cancel`)}
       onPress={onPress}>
       <ButtonText>{cta || _(msg`Cancel`)}</ButtonText>
@@ -163,7 +163,7 @@ export function Action({
     <Button
       variant="solid"
       color={color}
-      size={gtMobile ? 'small' : 'medium'}
+      size={gtMobile ? 'small' : 'large'}
       label={cta || _(msg`Confirm`)}
       onPress={handleOnPress}
       testID={testID}>