Add "fits valuesAndAttributes of" and "fits typesAndAttributes of"

[DaniRey]

It is sometimes interesting to not only test the minimal set of attributes and their values/types contained in the JSON, but also the maximum.

{
 "num": 123,
 "text": "abc"
}

would be valid for

json fits values of """{"num": 123}"""

but it would throw an error with

json fits valuesAndAttributes of """{"num": 123}"""

because it contains the attribute text, which is not part of the gauge.

The same should be true for

json fits types of """{"num": 1}"""

and

json fits typesAndAttributes of """{"num": 1}"""

Alternative name suggestions for valuesAndAttributes and typesAndAttributes are welcome.

[DaniRey]

This is superseeded by #112