Work on testing the Router

Completes the `Executed` enum in the router. Adds an `Escape` struct. Both are
needed for testing purposes.

Documents the gas constants in intent and reasoning.

Adds modernized tests around key rotation and the escape hatch.

Also updates the rest of the codebase which had accumulated errors.

processor/ethereum/src/primitives/block.rs

@@ -99,6 +99,7 @@ impl primitives::Block for FullEpoch {
       let Some(expected) =
         eventualities.active_eventualities.remove(executed.nonce().to_le_bytes().as_slice())
       else {
+        // TODO: Why is this a continue, not an assert?
         continue;
       };
       assert_eq!(