[Compiler][C++] Generate getter/setter/has/clear methods for c++

### Feature Request

Generate getter/setter/has/clear methods for c++

### Is your feature request related to a problem? Please describe

Currently generated c++ code has public struct fields, which should be encapsulated.

### Describe the solution you'd like

_No response_

### Describe alternatives you've considered

_No response_

### Additional context

#3099 