Add MultiBombe

Runs the Bombe multiple times with different rotor specs.
Edits the core BombeMachine a little to add the ability to switch rotors
without rewiring everything

src/core/lib/Enigma.mjs

@@ -171,6 +171,7 @@ class PairMapBase {
     constructor(pairs, name="PairMapBase") {
         // I've chosen to make whitespace significant here to make a) code and
         // b) inputs easier to read
+        this.pairs = pairs;
         this.map = {};
         if (pairs === "") {
             return;