New direct messages structure and endpoints

[ran5000]

Hello,

Is there a planned version to support the changes to the direct messages structure and endpoints outlines here: https://developer.twitter.com/en/docs/direct-messages/sending-and-receiving/guides/direct-message-migration

[shmargum]

I think this issue might be the same as #862 and #869

I have a pull request (#900) open that adds general support for making authenticated JSON post requests (currently post requests are all multipart/form-data)

I am hoping that it can be merged soon

[dancernerd32]

I am working toward a solution that will cover all of the direct message methods, change them to point to the new endpoints, and take the same parameters and return the same results as they did originally. I have what I believe is a pretty fleshed out solution, but some changes have been made to the code since I started, in some of the areas I was covering, so I need to change a few things before I put my PR in.

[sferik]

Closed via #927.