[Sequences] add a Tag property

[rhwy]

We would like to add a property to the sequences that qualifies them. It will allows us later to search for sequences that matches a certain Tag.

proposed:

{
    "Type": "Node",
    "Id": "MySequence",
    "Tags":["joke","story","detectives"]
}

Information:

• property name : Tag
• value type : array of strings
• attached : to root sequence element (node)