CORDA-943 - Fix trader demo

This is a multi issue problem
1. Fingerprinting of generics treats <T> and <?> differently, forcing
the evolver to be used when not needed

2. However, the evolver is required sometimes as generics are not
guaranteed to fingerprinting bi-directionally (thanks to type erasure of
deeply nested generic types). However, with serialization now writing
properties in a specific order, we need to ensure they're read back in
that order before applying them to an evolved constructor so as to
not corrupt the object reference cache

core/src/main/kotlin/net/corda/core/contracts/ContractState.kt

@@ -1,7 +1,6 @@
 package net.corda.core.contracts
 
 import net.corda.core.identity.AbstractParty
-import net.corda.core.identity.Party
 import net.corda.core.serialization.CordaSerializable
 
 // DOCSTART 1