SendVideo extends class KAbstractMultipartRequest while other Send objects still extend AbstractMultipartRequest

[mircoianese]

Hello,

The fact that class SendVideo is extending a different class from other send methods (SendMessage, SendPhoto...) could break compatibility.
For example I have some methods that take as input an AbstractSendRequest and that now are not compatible with SendVideo.

I think the solution should be to migrate all Send objects to KAbstractMultipartRequest and KAbstractSendRequest and then rename both back to AbstractMultipartRequest and AbstractSendRequest.

@anfanik @pengrad

[anfanik]

I'll do it

[ivanfmartinez]

@pengrad any ETA to release this changes as new version ? I have code that cannot be migrated to 8.3.0 because of this incompatibility with SendVideo