chore: Add down gem for Local file downloads (#2765)

- Add down gem to handle downloading files to host machine
- Remove the LocalResource class
- Introduce max limit for contact avatars send via SDK

Gemfile.lock

@@ -177,6 +177,8 @@ GEM
     dotenv-rails (2.7.6)
       dotenv (= 2.7.6)
       railties (>= 3.2)
+    down (5.2.3)
+      addressable (~> 2.8)
     dry-inflector (0.2.1)
     ecma-re-validator (0.3.0)
       regexp_parser (~> 2.0)
@@ -651,6 +653,7 @@ DEPENDENCIES
   devise-secure_password (~> 2.0)
   devise_token_auth
   dotenv-rails
+  down (~> 5.0)
   facebook-messenger
   factory_bot_rails
   faker