error message for [contains only] match should be improved

[ptrthomas]

Example:

* def response = [{a: 1}, {b: 2}]
* match response contains only [{a: 2}, {b: 2}]

results in super confusing and repetitive output. need to fix one of the loops or do a better diff algorithm at least for the error message

match failed: CONTAINS_ONLY
  $ | actual does not contain expected | actual array does not contain expected item - {"a":2} (LIST:LIST)
  [{"a":1},{"b":2}]
  [{"a":2},{"b":2}]

    $[1] | not equal | actual does not contain key - 'a' (MAP:MAP)
    {"b":2}
    {"a":2}

    $[0] | not equal | match failed for name: 'a' (MAP:MAP)
    {"a":1}
    {"a":2}

      $[0].a | not equal (NUMBER:NUMBER)
      1
      2