Fix rewards modal overflows + make it more theme friendly

[ghost]

Closes #1869
Closes #1848

[smk762]

Works, but if we can get it on to one line would be better.

I'd suggest locktime not set (is) and a small reduction of other columns (or column margin/padding). Might still be an overflow for other languages tho...

Heh, nevermind.

[ghost]

Works, but if we can get it on to one line would be better.

I'd suggest locktime not set (is) and a small reduction of other columns (or column margin/padding). Might still be an overflow for other languages tho...

Heh, nevermind.

Let's modernize rewards for another pr, I think we can do something better (cf. #1661)