fix: unsupported protocols for chained swaps are always unsupported

not only when the previous swap if of the same protocol!
Improve docs and naming

--- don't change below this line ---
ENG-4314 Took 15 minutes

src/encoding/evm/strategy_encoder/transfer_optimizations.rs

@@ -30,7 +30,6 @@ pub trait TransferOptimization {
         } else if (swap.token_in == wrapped_token) && wrap {
             // Wrapping already happened in the router so we can just use a normal transfer.
             TransferType::TransferToProtocol
-            // first swap
         } else if is_first_swap {
             if in_transfer_optimizable {
                 if permit2 {