Cash retrieval of SendTo menu items

refactoring: move the SendTo menu filling logic from KSnapshot to new class KSnapshotSendToActions

main.cpp: create 'window' on the stack to correctly call
KSnapshotSendToActions's dtor

CCBUG: 312495: the issues is not fixed yet,
but when the SendTo menu is clicked a second time it opens at once

REVIEW: 120920