Supporting jsdom with DataTransfer mock

[Fallenstedt]

I noticed your team has an amazing mock for the DataTransfer object: https://github.com/testing-library/user-event/blob/main/src/utils/dataTransfer/DataTransfer.ts#L138-L151

Would you team be open to using this code for jsdom? Currently, there is no mock for DataTransfer in jsdom. I'm unsure if there are concerns on your side of using your code in a PR for jsdom: jsdom/jsdom#1568