Changing the method name from "triggerMessage" to "displayActionMessage".

Generally speaking, I like to call the message at the bottom an "action message".
And things can "trigger" it, but in the case of a method that actually proactively displays the message, I find "displayActionMessage" to be a better name.

Also, removing package-lock files and improving code style

front/src/Api/iframe/Ui/ActionMessage.ts

@@ -0,0 +1,50 @@
+import {
+    MessageReferenceEvent,
+    removeActionMessage,
+    triggerActionMessage,
+    TriggerActionMessageEvent,
+} from "../../Events/ui/TriggerActionMessageEvent";
+import { queryWorkadventure } from "../IframeApiContribution";
+function uuidv4() {
+    return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(/[xy]/g, (c) => {
+        const r = (Math.random() * 16) | 0,
+            v = c === "x" ? r : (r & 0x3) | 0x8;
+        return v.toString(16);
+    });
+}
+
+export let triggerMessageInstance: ActionMessage | undefined = undefined;
+
+export class ActionMessage {
+    uuid: string;
+
+    constructor(private message: string, private callback: () => void) {
+        this.uuid = uuidv4();
+        if (triggerMessageInstance) {
+            triggerMessageInstance.remove();
+        }
+        triggerMessageInstance = this;
+        this.create();
+    }
+
+    async create() {
+        await queryWorkadventure({
+            type: triggerActionMessage,
+            data: {
+                message: this.message,
+                uuid: this.uuid,
+            } as TriggerActionMessageEvent,
+        });
+        this.callback();
+    }
+
+    async remove() {
+        await queryWorkadventure({
+            type: removeActionMessage,
+            data: {
+                uuid: this.uuid,
+            } as MessageReferenceEvent,
+        });
+        triggerMessageInstance = undefined;
+    }
+}