Enable sticker search by adding `searchfilter` option to search query

[alexbrazier]

It would be good to be able to search for stickers by using the searchfilter=sticker option

https://developers.google.com/tenor/guides/endpoints#parameters-search

callApi already takes in a params option that gets spread into the request, so it would probably be useful just to have access to that so that it's possible to pass any parameter into it.