This removes hardcoded actions from things like LineEdit and TextEdit.
Previously, things like copy, paste, etc were all hardcoded to Ctrl+C, Ctrl+V, etc. They could not be changed. This allows the possibility of them being changed, by making them use the action map. This has the added benefit of greatly simplifying the input handling logic in those controls. The logic which was previously in a huge and hard to follow switch statement has been extracted to individual methods.
