Moving mlog to corelibs (#16915)

* Moving mlog to corelibs

* Regenerating app layers

* Fix golangci-lint problem

* Fixing golangci-lint errors

* Renaming from corelibs to shared

* Renaming from corelibs to shared

* Fixing import

* Fixing merge problems

* Fixing build

services/tracing/tracing.go

@@ -14,7 +14,7 @@ import (
 	"github.com/uber/jaeger-client-go/zipkin"
 	"github.com/uber/jaeger-lib/metrics"
 
-	"github.com/mattermost/mattermost-server/v5/mlog"
+	"github.com/mattermost/mattermost-server/v5/shared/mlog"
 )
 
 // Tracer is a wrapper around Jaeger OpenTracing client, used to properly de-initialize jaeger on exit