MM-52532: Fix golangci warnings (#23709)

https://mattermost.atlassian.net/browse/MM-52532

- Replace golint with revive
- Add makezero linter
- Fix all the required linter failures

Some issues in enterprise and public modules
are yet to be fixed. We send this to expediate things.

server/channels/jobs/extract_content/worker.go

@@ -33,7 +33,7 @@ func MakeWorker(jobServer *jobs.JobServer, app AppIface, store store.Store) mode
 		jobServer.HandleJobPanic(job)
 
 		var err error
-		var fromTS int64 = 0
+		var fromTS int64
 		var toTS int64 = model.GetMillis()
 		if fromStr, ok := job.Data["from"]; ok {
 			if fromTS, err = strconv.ParseInt(fromStr, 10, 64); err != nil {

server/channels/jobs/product_notices/scheduler.go

@@ -14,7 +14,7 @@ type Scheduler struct {
 	*jobs.PeriodicScheduler
 }
 
-func (scheduler *Scheduler) NextScheduleTime(cfg *model.Config, now time.Time, pendingJobs bool, lastSuccessfulJob *model.Job) *time.Time {
+func (scheduler *Scheduler) NextScheduleTime(cfg *model.Config, _ time.Time, pendingJobs bool, lastSuccessfulJob *model.Job) *time.Time {
 	nextTime := time.Now().Add(time.Duration(*cfg.AnnouncementSettings.NoticesFetchFrequency) * time.Second)
 	return &nextTime
 }