ChatMemberXXX redesign

[Badiboy]

@coder2020official

Looks like we need to redesign ChatMemberXXX family. Currently we have all-in-one ChatMember, but it does not correspond to API.

https://core.telegram.org/bots/api#chatmember

I don't remeber why it is done like this now, I suppose we left it for compatibility...

[coder2020official]

I'll take a look into it.

I don't remember any backward compatibility choices, though. All I remember is that Swiss was the one to implement it :)

[Badiboy]

AFAIR some time before there was a single class ChatMember, which was later split into children. Thus we save full ChatMember to leave compatibility.

[coder2020official]

not really having time rn. Could you do so?