[task scheduler] Move files from build_scheduler/ to task_scheduler/

task_scheduler/go/db/comments.go

 package db
 
 import (
         "bytes"
         "encoding/gob"
         "fmt"
         "sync"
         "time"
 
         "github.com/skia-dev/glog"
@@ skipping 480 matching lines @@
                 if err := b.write(); err != nil {
                         // If write returns an error, we must revert to previous.
                         if putErr := b.putCommitComment(existing); putErr != nil {
                                 glog.Warning("Unexpected error: %s", putErr)
                         }
                         return err
                 }
         }
         return nil
 }