execute `ValidateBlock` in fullsync

### What would you like to be added

also check `ValidateBlock` during fullsync

### Why is this needed

Ensure that the new code is compatible with the history block

### How important you think this is for IoTeX
- [x] must have
- [] should have
- [] 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)