:fast_forward: type defintations required for Operations and Cursor

# Feature Request
type Operations and type Cursor implementation

## Summary
define the following types
- ### Cursor
```
A vector of id that uniquely identify the path in Node tree.
```
- ### Operation 
```
{
    id: LamportCounter
    deps: []LamportCounter
    cursor: Cursor
    mutation: ASSIGN | DELETE | INSERT | GET
    value: *Node
}
```