new panel to create keys from scratch

The configuration editor as it is now can create new key only by cloning the old ones.

We need a panel to create from scratch new keys. Ideally the first operation is the creation of a new configmode. After that the l1ce should request to create a new key, possibly proposing the tables that can be used, or discard the insertion. As a refinement, the l1ce may ask if the user wants to clone an existing key or a have blank skeleton.