Improve Account settings tab

[voltangle]

There are two things that are bad about he current account settings page: bad performance and a lot of stuff does not work

Performance

The main bottleneck is that it uses a very bad method of fetching images, it basically downloads all profile photos, and then shows them, which is pretty stupid, knowing that we already have AsyncTdImage, which does this asynchronously.

Functionality

It's also pretty simple, because there is nothing that requires something very cool and hard to implement, just improve the design here and there, and add functionality to number changing button and to profile photo change button.