[FEATURE] Add Update.effective_sender

[Poolitzer]

We have Update.effective_user for the sender of the message. This attribute however misses out on the anonymous sender info provided in Message.sender_chat, MessageReactionUpdated.action_chat and Poll.voter_chat.

I would propose adding a new shortcut to the Update class, effective_sender. It either returns the sender chats above or effective_user, if they are not set.

[nemo-1999]

Hi, I would like to work on this

[Poolitzer]

Alright, have fun!

[Bibo-Joshi]

@Poolitzer Please keep in mind that this is dependent on the ongoing API 7.0 pr

[Poolitzer]

Oh right, you should base your branch on this. So either wait until it is merged with master and then do the PR or branch it on the api branch and PR towards it if you are eager to do it now.

[nemo-1999]

I can wait. Until then I can take a look at the code base and understand the req better

[harshil21]

I can wait. Until then I can take a look at the code base and understand the req better

@nemo-1999 you may start working on this now since it's already merged to master