Add configuration for sharing emoji packs

This adds the configuration interface for the endpoints introduced here.

build/webpack.dev.conf.js

@@ -48,7 +48,7 @@ const devWebpackConfig = merge(baseWebpackConfig, {
       poll: config.dev.poll
     },
     headers: {
-      'content-security-policy': "base-uri 'self'; frame-ancestors 'none'; img-src 'self' data: https:; media-src 'self' https:; style-src 'self' 'unsafe-inline'; font-src 'self'; manifest-src 'self'; script-src 'self';"
+      'content-security-policy': "base-uri 'self'; frame-ancestors 'none'; img-src 'self' data: https: http:; media-src 'self' https:; style-src 'self' 'unsafe-inline'; font-src 'self'; manifest-src 'self'; script-src 'self';"
     }
   },
   plugins: [