CORE-16860 Add counterparty info request and response events (#1256)

Adds counterparty info request and response events, and removes unneeded flow events and states.

The session changes introduced in 5.1 mean that it is possible to request counterparty information before the counterparty is aware the flow exists and has started its initiated flow. This change allows the act of requesting counterparty information to start the initiated flow if required.

---------

Co-authored-by: James Higgs <[email protected]>

data/avro-schema/src/main/resources/avro/net/corda/data/flow/event/FlowEvent.avsc

@@ -11,7 +11,6 @@
       "name": "payload",
       "type": [
         "net.corda.data.flow.event.StartFlow",
-        "net.corda.data.flow.event.Wakeup",
         "net.corda.data.flow.output.FlowStatus",
         "net.corda.data.flow.event.SessionEvent",
         "net.corda.data.flow.event.external.ExternalEventResponse"

data/avro-schema/src/main/resources/avro/net/corda/data/flow/event/SessionEvent.avsc

@@ -50,8 +50,8 @@
     {
       "name": "payload",
       "type": [
-        "net.corda.data.flow.event.session.SessionInit",
-        "net.corda.data.flow.event.session.SessionConfirm",
+        "net.corda.data.flow.event.session.SessionCounterpartyInfoRequest",
+        "net.corda.data.flow.event.session.SessionCounterpartyInfoResponse",
         "net.corda.data.flow.event.session.SessionData",
         "net.corda.data.flow.event.session.SessionClose",
         "net.corda.data.flow.event.session.SessionError"

data/avro-schema/src/main/resources/avro/net/corda/data/flow/event/session/SessionCounterpartyInfoRequest.avsc

@@ -0,0 +1,13 @@
+{
+  "type": "record",
+  "name": "SessionCounterpartyInfoRequest",
+  "doc" : "Request counterparties flow session information. This includes the flow protocol version that they are running.",
+  "namespace": "net.corda.data.flow.event.session",
+  "fields": [
+    {
+      "name": "sessionInit",
+      "type": "net.corda.data.flow.event.session.SessionInit",
+      "doc": "Contains information that can be used to start an initiated flow. Will be null for messages sent to the initiator. Will be null when initiated party is confirmed to be present to ensure out of order messages that arrive first contain this info."
+    }
+  ]
+}

data/avro-schema/src/main/resources/avro/net/corda/data/flow/event/session/SessionCounterpartyInfoResponse.avsc

@@ -0,0 +1,7 @@
+{
+  "type": "record",
+  "name": "SessionCounterpartyInfoResponse",
+  "doc" : "Sent from initiated to initiating party to inform them which protocol version of the flow they are running.",
+  "namespace": "net.corda.data.flow.event.session",
+  "fields": []
+}

gradle.properties

@@ -9,7 +9,7 @@ cordaProductVersion = 5.1.0
 # NOTE: update this each time this module contains a breaking change
 ## NOTE: currently this is a top level revision, so all API versions will line up, but this could be moved to
 ##   a per module property in which case module versions can change independently.
-cordaApiRevision = 20
+cordaApiRevision = 21
 
 # Main
 kotlinVersion = 1.8.21