Refactor the Avatar component & review its usage to improve consistency

[toiletgranny]

Description

There are a few known issues with the current Avatar component design & implementation, the most prominent one being the inconsistent usage in whether it's linking anywhere and have its own distinctive states, or not.

Figma link

https://www.figma.com/file/Pf31tuYpozYmpq163U2ho8/Web-components?node-id=104%3A76

How urgent this is?

Not a blocker, but still worth considering

[toiletgranny]

+Consider introducing 16px variant.