MM-49354: Make compliance export query cancellable (#21943)

We accept a context that can cancel the query.
This allows us to exit a job faster.

```release-note
Compliance export job can now cancel the SQL query
execution during server shutdown which will allow
the job to exit faster.
```

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/timerlayer/timerlayer.go

@@ -2932,10 +2932,10 @@ func (s *TimerLayerComplianceStore) GetAll(offset int, limit int) (model.Complia
 	return result, err
 }
 
-func (s *TimerLayerComplianceStore) MessageExport(cursor model.MessageExportCursor, limit int) ([]*model.MessageExport, model.MessageExportCursor, error) {
+func (s *TimerLayerComplianceStore) MessageExport(ctx context.Context, cursor model.MessageExportCursor, limit int) ([]*model.MessageExport, model.MessageExportCursor, error) {
 	start := time.Now()
 
-	result, resultVar1, err := s.ComplianceStore.MessageExport(cursor, limit)
+	result, resultVar1, err := s.ComplianceStore.MessageExport(ctx, cursor, limit)
 
 	elapsed := float64(time.Since(start)) / float64(time.Second)
 	if s.Root.Metrics != nil {