Support array result include sequence action

[ningyougang]

Depend on below prs:

• Support array result for common action and sequence action openwhisk#5290 (If want to this pr's travis ci passed, should merge 5290 firstly)

• Support array result

  • make dotnet runtime to support array result for common action
  • make dotnet runtime to support array result for sequence action (support array as input param)

[ningyougang]

Steps of test support sequence action

• Write Split.cs and Sort.cs

using System;
using Newtonsoft.Json.Linq;

namespace Apache.OpenWhisk.Example.Dotnet
{
    public class Split
    {
        public JArray Main(JObject args)
        {
            JArray jarray = new JArray();
            jarray.Add("e1");
            jarray.Add("e2");
            // use Jarray param as next action's input param
            return (jarray);
        }
    }
}

using System;
using Newtonsoft.Json.Linq;

namespace Apache.OpenWhisk.Example.Dotnet
{
    public class Sort
    {
        public JArray Main(JArray args)
        {
            // Don't do real sort operation, just return Jarray direclty, don't do real split operation
            return (args);
        }
    }
}

• Create the action and invoke it
  refer to: https://oss.navercorp.com/lambda/lambda/blob/master/docs/actions-dotnet.md

wsk -i action update /whisk.system/utils/splitDotNet splitDotNet.zip --main Apache.OpenWhisk.Example.Dotnet::Apache.OpenWhisk.Example.Dotnet.Split::Main --kind dotnet:2.2
wsk -i action update /whisk.system/utils/sortDotNet sortDotNet.zip --main Apache.OpenWhisk.Example.Dotnet::Apache.OpenWhisk.Example.Dotnet.Sort::Main --kind dotnet:2.2
wsk -i action create mySequence-dotnet --sequence /whisk.system/utils/splitDotNet,/whisk.system/utils/sortDotNet 
wsk -i action invoke --result mySequence-dotnet -r -v

[dgrove-oss]

LGTM