feat(config): read write timeout value

This commit adds a write timeout configuration parameter. As it is part
of the downloading cycle, it is available under
`blocking/loading/downloads`.
The default value comes from `server/http.go` line 23.

Refs: 0xERR0R#1606

config/config.go

@@ -405,9 +405,10 @@ func recoverToError(do func(context.Context) error, onPanic func(any) error) fun
 }
 
 type Downloader struct {
-	Timeout  Duration `yaml:"timeout" default:"5s"`
-	Attempts uint     `yaml:"attempts" default:"3"`
-	Cooldown Duration `yaml:"cooldown" default:"500ms"`
+	Timeout      Duration `yaml:"timeout" default:"5s"`
+	WriteTimeout Duration `yaml:"writeTimeout" default:"20s"`
+	Attempts     uint     `yaml:"attempts" default:"3"`
+	Cooldown     Duration `yaml:"cooldown" default:"500ms"`
 }
 
 func (c *Downloader) LogConfig(logger *logrus.Entry) {