reference global logrus (#274)

* reference logrus' global logger instead of passing and storing a logger reference everywhere

* always directly use global logrus logger instead of referencing an instance

* test suites should also directly use the global logrus logger

* rename gin logging function to clarify that it's middleware

* correct comments which erroneously referenced removed logger parameter

* setting log level for tests now uses logrus' exported type instead of the string value, to guarantee error isn't possible

internal/api/s2s/nodeinfo/nodeinfoget.go

@@ -28,7 +28,7 @@ import (
 // NodeInfoGETHandler returns a compliant nodeinfo response to node info queries.
 // See: https://nodeinfo.diaspora.software/
 func (m *Module) NodeInfoGETHandler(c *gin.Context) {
-	l := m.log.WithFields(logrus.Fields{
+	l := logrus.WithFields(logrus.Fields{
 		"func":       "NodeInfoGETHandler",
 		"user-agent": c.Request.UserAgent(),
 	})