Add helloevent

Signed-off-by: Stanislav Bogatyrev <s.bogatyrev@yadro.com>

l3/helloevent/go.mod

@@ -0,0 +1,5 @@
+module helloevent
+
+go 1.20
+
+require github.com/nspcc-dev/neo-go/pkg/interop v0.0.0-20231108063405-7045d3bd63d9

l3/helloevent/go.sum

@@ -0,0 +1,2 @@
+github.com/nspcc-dev/neo-go/pkg/interop v0.0.0-20231108063405-7045d3bd63d9 h1:VcjYKiGIn4EuUfibi4QI6lWkAFfg7PTYL8TxMvd+7Ck=
+github.com/nspcc-dev/neo-go/pkg/interop v0.0.0-20231108063405-7045d3bd63d9/go.mod h1:J/Mk6+nKeKSW4wygkZQFLQ6SkLOSGX5Ga0RuuuktEag=

l3/helloevent/helloevent.go

@@ -0,0 +1,15 @@
+package helloevent
+
+import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
+
+var notificationName string
+
+// init initializes notificationName before calling any other smart-contract method
+func init() {
+	notificationName = "HelloWorld"
+}
+
+// RuntimeNotify sends runtime notification with "HelloWorld" name
+func RuntimeNotify(args []any) {
+    runtime.Notify(notificationName, args)
+}

l3/helloevent/helloevent.yml

@@ -0,0 +1,10 @@
+name: "helloevent"
+sourceurl: https://git.frostfs.info/Web3N3/web3-course
+supportedstandards: []
+events:
+  - name: HelloWorld
+    parameters:
+      - name: args
+        type: Array
+permissions:
+  - methods: '*'