Add avatar max size limit

shared/models/server-config.model.ts

@@ -5,4 +5,17 @@ export interface ServerConfig {
   transcoding: {
     enabledResolutions: number[]
   }
+  avatar: {
+    file: {
+      size: {
+        max: number
+      },
+      extensions: string[]
+    }
+  }
+  video: {
+    file: {
+      extensions: string[]
+    }
+  }
 }