feat(node): [NET-1381] Add version to operator heartbeats (#2918)

Add `applicationVersion` field to the heartbeat message (published by
`announceNodeToStream`).

## Testing

Manually tested that the schema validation in v101 accepts the message
which has the additional version field. This test snippet passes in a
temp branch which was checked out from the v101.1.2 tag:
```ts
it('v102 messages passes validation in v101 schema', () => {
    const msg = {
        "msgType": "heartbeat",
        "peerDescriptor": {
            "nodeId": "nodeId",
            "websocket": {
                "port": 31313,
                "host": "127.0.0.1",
                "tls": false
            }
        },
        "applicationVersion": "102.0.0-beta.1"
    }
    expect(() => HeartbeatMessageSchema.parse(msg)).not.toThrow()
})
```

Author: teogeb

packages/node/src/plugins/operator/heartbeatUtils.ts

@@ -1,5 +1,6 @@
-import { z } from 'zod'
 import { NetworkNodeType, NetworkPeerDescriptor } from '@streamr/sdk'
+import { z } from 'zod'
+import { version as applicationVersion } from '../../../package.json'
 
 export const HeartbeatMessageSchema = z.object({
     msgType: z.enum(['heartbeat']),
@@ -12,14 +13,16 @@ export const HeartbeatMessageSchema = z.object({
             tls: z.boolean()
         })),
         region: z.optional(z.number())
-    })
+    }),
+    applicationVersion: z.optional(z.string())  // optional for backward compatibility (written from v102 onward)
 })
 
 export type HeartbeatMessage = z.infer<typeof HeartbeatMessageSchema>
 
 export function createHeartbeatMessage(peerDescriptor: NetworkPeerDescriptor): HeartbeatMessage {
     return {
         msgType: 'heartbeat',
-        peerDescriptor
+        peerDescriptor,
+        applicationVersion
     }
 }

packages/node/test/integration/plugins/operator/announceNodeToStream.test.ts

@@ -1,6 +1,7 @@
 import { _operatorContractUtils } from '@streamr/sdk'
 import { fastPrivateKey, generateWalletWithGasAndTokens } from '@streamr/test-utils'
 import { collect, toEthereumAddress } from '@streamr/utils'
+import { version as applicationVersion } from '../../../../package.json'
 import { announceNodeToStream } from '../../../../src/plugins/operator/announceNodeToStream'
 import { formCoordinationStreamId } from '../../../../src/plugins/operator/formCoordinationStreamId'
 import { createClient } from '../../../utils'
@@ -26,7 +27,8 @@ describe('announceNodeToStream', () => {
         const [{ content }] = await collect(subscription, 1)
         expect(content).toEqual({
             msgType: 'heartbeat',
-            peerDescriptor: await client.getPeerDescriptor()
+            peerDescriptor: await client.getPeerDescriptor(),
+            applicationVersion
         })
 
         await anonymousClient.destroy()

packages/node/test/unit/plugins/operator/heartbeatUtils.test.ts

@@ -1,5 +1,6 @@
-import { createHeartbeatMessage, HeartbeatMessageSchema } from '../../../../src/plugins/operator/heartbeatUtils'
+import { omit } from 'lodash'
 import { ZodError } from 'zod'
+import { createHeartbeatMessage, HeartbeatMessageSchema } from '../../../../src/plugins/operator/heartbeatUtils'
 
 describe('heartbeatUtils', () => {
     it('messages created with createHeartbeatMessage pass validation', () => {
@@ -14,6 +15,21 @@ describe('heartbeatUtils', () => {
         expect(() => HeartbeatMessageSchema.parse(msg)).not.toThrow()
     })
 
+    it('messages without version pass validation', () => {
+        const msg = omit(
+            createHeartbeatMessage({
+                nodeId: 'nodeId',
+                websocket: {
+                    port: 31313,
+                    host: '127.0.0.1',
+                    tls: false
+                }
+            }),
+            'applicationVersion'
+        )
+        expect(() => HeartbeatMessageSchema.parse(msg)).not.toThrow()
+    })
+
     it('invalid message does not pass validation', () => {
         const msg = createHeartbeatMessage({
             foo: 'bar'