Make property names more descriptive

[JasperVercammen]

It's hard to understand some property names in the CookieToaster:
accept -> it's a function, so better name it: onCookiesAccepted (or something like that)
decline -> Same
popped -> I have acctually no idea what 'popped' means for a cookietoaster :-)

SamJS/src/components/cookieToaster/CookieToaster.js

Line 62 in d2b7a5a

accept: PropTypes.func,