[{_id:1,labels:[{name:" String",category:"String"},{name:"String ",category:"String"},{name:" String ",category:"String"}]}]

db.collection.update({"labels.name":{$regex:"^ | $"}},[{$set:{labels:{$map:{input:"$labels",in:{category:"$$this.category",name:{$trim:{input:"$$this.name"}}}}}}}],{multi:true})