Allow image panes to be used for avatars

[ahuang11]

import panel as pn
pn.extension()

chat = pn.chat.ChatInterface(avatar=pn.pane.Image("https://panel.holoviz.org/_static/logo_horizontal.png"))
chat

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (34df686) 83.99% compared to head (d1ad443) 83.99%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5870   +/-   ##
=======================================
  Coverage   83.99%   83.99%           
=======================================
  Files         290      290           
  Lines       42400    42411   +11     
=======================================
+ Hits        35612    35624   +12     
+ Misses       6788     6787    -1     

Flag	Coverage Δ
ui-tests	40.88% <68.42%> (+<0.01%)	⬆️
unitexamples-tests	72.34% <100.00%> (+<0.01%)	⬆️

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[AlbertDeFusco]

Maybe this should be ImageBase like it is for Feed?

panel/panel/chat/message.py

Line 39 in 34df686

Avatar = Union[str, BytesIO, ImageBase]

[ahuang11]

Thanks @AlbertDeFusco for reviewing. I just removed it since it's not used anywhere and param cannot accept typing types.

[AlbertDeFusco]

This looks correct to me!

[philippjfr]

Looks great, thanks for providing review @AlbertDeFusco !