Data center visualization

Changes:
* new view ``DataCenterView``.
```
.data_center .grid .grid_wrapper {
  position: relative;
  min-height: 800px;
  background-color: transparent;
  background-image: 
    linear-gradient(0deg, rgba(255, 255, 255, 0.5) 0%, rgba(255, 255, 255, 0.5) 1%, transparent 2%, transparent),  
    linear-gradient(90deg, rgba(255, 255, 255, 0.5) 0%, rgba(255, 255, 255, 0.5) 1%, transparent 2%, transparent);
  background-size: 40px 40px;
}
```
looks better.