Draft: Make chatbar extend all the way with reasonable padding/margins

This MR:

• makes the chatbar extend all the way
• increases the height of the userinfo bar
• aligns the height of the userinfo bar, the chatbar, and the right tab bar
• consequently, it also increases the height of the chatbar (which also means a larger click target)

You should test this locally with other resolutions and scalings since the increase to the chatbar is very significant. I tested this in both 1366x768 and 1920x1080, but I do use font size 12 with 100% scaling, which makes it more proportional to the image size so the screenshots can be misleading.

Current state	With this MR