[Feature]: Add close button to Currencies window, and hide zeroed currencies

[silverhawke249]

Describe the feature

it would be nice to be able to dismiss the Currencies window by clicking the [X] button that is conspicuously missing from the top right of that window.

also, have an option to hide currencies that we have 0 of? it's nice to hide clutter.

Describe the implementation

Literally just add the [X] button to this window:

Maybe add a tickbox at the bottom/top of currencies window like "[v] Hide currencies at zero"

[Cidan]

Will definitely add close button.

[AMaribo]

The close button has been added.