the original layout is actually more space efficient if using CardFrame
instead of CardInfoWidget and reducing the size of the deck editor
toolbar.

this commit also removes the old search feature by removing the search
button and the clear search button. the clear search menu item is left
in place, however it now clears the filtertree.

finally, the stretch factor for the right frame in the main layout was
reduced to zero so that the card database gets priority for extra space.
this makes more sense because the deck editor does not actually need
very much horizontal space.

renamed filter list modules to filter tree to more accurately reflect
the nature of the data structure.

also refactored much of the filter list code to be much
cleaner and modular.

enable/disable check boxes still not functional

filter builder takes filter options from user, then adds
completed filters to the filter tree. the filter tree does
not currently do anything. in the future it will filter the
cards in the database view.