Function compareKeys

compareKeys(
a: object,
b: object,
): { a: string[]; b: string[]; isSame: boolean; shared: string[] }
Compares the keys of two objects, returning a set of those in common, and those in either A or B exclusively.
```
const a = { colour: `red`, intensity: 5 };
const b = { colour: `pink`, size: 10 };
const c = compareKeys(a, b);
// c.shared = [ `colour` ]
// c.a = [ `intensity` ]
// c.b = [ `size`  ]
```
Parameters
- a: object
- b: object
Returns { a: string[]; b: string[]; isSame: boolean; shared: string[] }