[2021] Vex and Veigar should be friends and have champion specific dialogue

Veigar hasn't gotten any new audio in a while, so I think it could be super neat to have the new gloomy yordle be friends with our resident master of darkness. These two are perfect compatriots! If Vex is able to be played as a support, Vex+Veigar bot lane will be cute and scary.

Anyway, I really hope these two dark yordles get along.