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/app/team.go

@@ -234,7 +234,7 @@ func (a *App) createOnboardingLinkedBoard(c request.CTX, teamId string) (*fb_mod
 		return nil, appErr
 	}
 
-	var template *fb_model.Board = nil
+	var template *fb_model.Board
 	for _, t := range templates {
 		v := t.Properties["trackingTemplateId"]
 		if v == welcomeToBoardsTemplateId {