Improve object.matching error report

[SimoneGianni]

Currently it is almost unreadable in a vscode error report.

It should look something like this:

{
  a: 1, // OK, expecting a number
  b: 5, // ----> ERROR: was expecting a string
  c: { // OK, expecting an object 
    d:1, 
    e:4,
  },
  f: { // ----> ERROR
    g: 3, // OK
    h: 7, // ----> ERROR: was expecting 9
  }
}