Define and support vertex and edge visibility via native HBase visibility

JanusGraph has preliminarily defined 'visibility'
```
/**
* Returns true if this storage backend supports entry-level visibility by attaching a visibility or authentication
* token to each column-value entry in the data store and limited retrievals to "visible" entries.
*
* @return
*/
boolean hasVisibility();
```
```
public enum EntryMetaData {

TTL(Integer.class, false, data -> data instanceof Integer && ((Integer) data) >= 0L),
VISIBILITY(String.class, true, data -> data instanceof String && StringEncoding.isAsciiString((String) data)),
TIMESTAMP(Long.class, false, data -> data instanceof Long);
```
But nothing has been further done and supported yet.

Here we will try to define and support vertex and edge visibility via native HBase cell level visibility.