feat(setting): Implemented the settings administrative menu

lib/config/overrides.go

@@ -76,6 +76,10 @@ func (cfg *Config) assignInt64(key string, value int64, source Source) {
 		cfg.MaxGuestExpirySeconds = value
 	case SettingOneTimeDownloadExpirySecs:
 		cfg.OneTimeDownloadExpirySeconds = value
+	case SettingGlobalMaxFileSizeBytes:
+		cfg.GlobalMaxFileSizeBytes = value
+	case SettingGlobalMaxBoxSizeBytes:
+		cfg.GlobalMaxBoxSizeBytes = value
 	case SettingDefaultUserMaxFileBytes:
 		cfg.DefaultUserMaxFileSizeBytes = value
 	case SettingDefaultUserMaxBoxBytes:
@@ -113,3 +117,10 @@ func (cfg *Config) sourceFor(key string) Source {
 	}
 	return source
 }
+
+func (cfg *Config) DefaultValue(key string) string {
+	if cfg.defaults == nil {
+		return ""
+	}
+	return cfg.defaults[key]
+}