[new rule]: avoid models only have one property

### Lint rule description

Some models are only have one property might for extensibility concern, but most of these models will not be changes as the overall design principle is avoiding breaking change.

### Related swagger example

N

### Category

SDK

### Severity level

Warning

### Applies to

Management plane API spec, Data plane API spec

### How to fix the violation

Group more property or not define a new model

### What't the impact if breaking the rule

User experience.