Adding the ability to inject websites directly inside maps

This PR adds the ability to inject a website INSIDE a map (as an iframe inside a Phaser HTML object)
The iFrame will be rendered transparently, unless you set a background-color on the body, which opens a number of cool possibilities.

Needs to be done: allowing the iframe API in those iframes.

front/src/Phaser/Map/PropertyUtils.ts

@@ -0,0 +1,36 @@
+import type { ITiledMapProperty } from "./ITiledMap";
+
+export class PropertyUtils {
+    public static findProperty(
+        name: string,
+        properties: ITiledMapProperty[] | undefined
+    ): string | boolean | number | undefined {
+        return properties?.find((property) => property.name === name)?.value;
+    }
+
+    public static mustFindProperty(
+        name: string,
+        properties: ITiledMapProperty[] | undefined,
+        context?: string
+    ): string | boolean | number {
+        const property = PropertyUtils.findProperty(name, properties);
+        if (property === undefined) {
+            throw new Error('Could not find property "' + name + '"' + (context ? " (" + context + ")" : ""));
+        }
+        return property;
+    }
+
+    public static mustFindStringProperty(
+        name: string,
+        properties: ITiledMapProperty[] | undefined,
+        context?: string
+    ): string {
+        const property = PropertyUtils.mustFindProperty(name, properties, context);
+        if (typeof property !== "string") {
+            throw new Error(
+                'Expected property "' + name + '" to be a string. ' + (context ? " (" + context + ")" : "")
+            );
+        }
+        return property;
+    }
+}