CORDA-786 - Use reflection to infer proxy and proxied types in CorDapp custom serializers

This removes any need for the user implement and override types from the
super class

    * CORDA-786 - Docs update
    * CORDA-786 - Remove unneeded second annotation on the proxy objects
    * Fix merge conflicts

testing/test-utils/src/main/kotlin/net/corda/testing/SerializationTestHelpers.kt

@@ -104,6 +104,7 @@ private fun createTestSerializationEnv(label: String) = object : SerializationEn
         },
         AMQP_P2P_CONTEXT,
         KRYO_RPC_SERVER_CONTEXT,
+        KRYO_RPC_CLIENT_CONTEXT,
         AMQP_STORAGE_CONTEXT,
         KRYO_CHECKPOINT_CONTEXT) {
     override fun toString() = "testSerializationEnv($label)"

testing/test-utils/src/main/kotlin/net/corda/testing/node/MockCordappProvider.kt

@@ -22,7 +22,6 @@ class MockCordappProvider(cordappLoader: CordappLoader, attachmentStorage: Attac
                 schedulableFlows = emptyList(),
                 services = emptyList(),
                 serializationWhitelists = emptyList(),
-                serializationCustomSerializerProxies = emptyList(),
                 serializationCustomSerializers = emptyList(),
                 customSchemas = emptySet(),
                 jarPath = Paths.get(".").toUri().toURL())