Issue with MacOS Mojave dark mode

[aguycalled]

The GUI does not render correctly the colors when using MacOS Mojave in dark mode.

Examples:

Address not showing, background for text field amount is black

Black background

[matt-auckland]

I think for now we just disable dark mode: https://github.com/bitcoin/bitcoin/pull/14593/files

Optimising the wallet for dark mode will be a moderate amount of effort