feat: revamp thread screen

[urmauur]

• Thread screen is default screen
• Screen blank state when user have not any model
• Change create thread using icon instead of button
• Update ribbon menu icon
• Update Message toolbar height when user typing long message
• Add default avatar placeholder
• Update message action toolbar
• Update right panel visual to latest design on Figma
• New component select or dropdown
• Initial system monitor screen
• Move list downloaded model into settings screen

[freelerobot]

@urmauur I think the dropdown icon is reversed.

• ^ is when the section is collapsed. Clicking on it should open the section
• v is when the section is opened. Clicking on it should close the section

See below:

In this state, the icon should be `v` instead of `^`

[imtuyethan]

@0xSage actually the current one is correct:
^ is when the section is opened.
v is when the section is collapsed

Ref: https://carbondesignsystem.com/components/accordion/usage/

[freelerobot]

@imtuyethan you are right, I was wrong about the direction.

I did a lot of googling, but this seems to sum it up from a vernacular standpoint:
https://ux.stackexchange.com/questions/117866/what-expand-collapse-representation-is-correct

My apologies @urmauur is it possible to switch it back.

[urmauur]

@0xSage @imtuyethan okay