Numeric enums selection

Add ability to choose enums items by numbers in addition to names

For example, for that enum
```Java
public enum Semester {
    FIFTH("fifth"),
    SIXTH("sixth"),
    SEVENTH("seventh"),
    EIGHTH("eighth");
}
```
CLI should output:
```
Choose semester:
0 - fifth
1 - sixth
2 - seventh
3 - eighth
```