Visual Issues - Avatar Group

[droshev]

• Avatar Group - dark theme; menu header border color is different than the body border in Dark theme

• Avatar Group - menu arrow LTR is not centered (feat: Avatar Group overflow spacing and overflow button border color #2121)

[N1XUS]

@droshev as discussed:

• First item has been fixed
• Second item is not possible to achieve with static nature of the fundamental styles. Yet, it can be achieved in fundamental ngx. Further discussion on implementation for fundamental ngx is required.