EuiComboBox and EuiColorPicker don't allow prepend and append

[miukimiu]

EuiComboBox and EuiColorPicker don't allow prepend and append.

For instance, the maps team is using a EuiComboBox and a EuiColorPicker and that's the result:

Ideally, both components should allow prepend and append as the EuiFieldText allows.

[miukimiu]

I just added the append and prepend to the EuiComboBox without too much thinking and that was the result:

So I need to rethink the design. 😛

[thomasneirynck]

Thanks for creating this. +1, it would really clean up the styling UX in Maps.

[miukimiu]

I'm closing this issue in favor of #2943