Support example static values for collection elements

[apenlor]

Right now there is no option to generate a collection with static values, they always have to be random

@PactDslBodyBuilder
public class Student {

    @Example("idSample")
    private List<String> id;
}

Output

{
  "id" : [ "fVuayin3uOzdV" ]
}

As a developer, I need to have the option to define those values.

One alternative may be to accept as example collections in string format, like these:

@Example("[\"one\", \"two\", \"three\"]")
private List<String> stringList;

@Example("[1, 2, 3]")
private Set<Integer> integerSet;

@Example("{\"key1\": 1, \"key2\": 2, \"key3\": 3}")
private Map<String, Integer> stringToIntegerMap;