Empty tables do not look good

[madvas]

Throughout the app there are multiple instances where we show empty tables, which don't look very good and give off feeling of broken app. Instead of showing empty table, we can just show there center-aligned text such as "There's no activity yet," or "There are no proposals yet.".

Bonus points: As you can see in the images, in dark mode the pagination buttons have broken color. Arrows can stay white, but circle around should have darker tint.

[madis]

Fixed like this. Shown is the default message, which can be customized for each c-table via :empty-message param