VaAvatar deforms non-square images

[bagrovYKT]

Vuestic-ui version: 1.9.8

Description

VaAvatar is currently generate an img tag, which is sensitive to aspect ratio of the source image. So, when it's not 1:1, it is impossible to use VaAvatar component because it deforms image.
However, there is a best-practice for this case to use background-image style property with background-size: cover, background-position: center center instead of img tag. So, i think VaAvatar component should be refactored for properly displayed non-square images.

Best regards to all the contribute team!