e2etest support for rolldpos

### What would you like to be added

as title

### Why is this needed

Currently, e2etest only supports standalone mode and cannot cover testing in aspects such as consensus and p2p

### How important you think this is for IoTeX
- [x] nice to have

### Additional information
Let us know any background or context that would help us better understand the request (for example the particular use-case that prompted this request)