Make `send_payment_with_route` take `Route` by value

Make `send_payment_with_route` take `Route` by value

Now that `ChannelManager::send_payment_with_route` is deprecated,
we don't care too much about making it as effecient as possible, so
there's not much cost to making it take `Route` by value. This
avoids bindings being unsure if the by-reference `Route` passed
needs to outlive the `ChannelManager` itself or if it only needs to
outlive the method call, creating some call overhead by forcing a
`Route::clone`, but avoiding a memory leak.