Possibility of having a ExtraSmall variant for icon buttons

[tqwewe]

The smallest variant for a button is ButtonSize::Small, however this icon can be a little big for some uses cases, despite it being the smallest variant.

The icon size when using ButtonSize::Small is 20px, but it can look out of place due to it being a little big. Many button icons, including the ones seen in Github toolbar and grafana dashboard are 16px or 18px.

Example of Github button icons (16px icon size):

Example of Grafana button icons (18px icon size):

Example of Thaw UI small button icon size (20px icon size) used in a card header which looks a little oversized compared to the text:

For additional context, here's the button sizes I observe in the UI libraries mentioned as resources in Thaw's README:

• Fluent UI - 20px
• Pigment - couldn't find the exact size, but I see they also have extra small variant, so likely below 20px
• Naive UI - 18px