UWP parser requires "type": "Column" when it's not necessary

Accepted, task list:

• TypeScript
• UWP (PR #555)
• Android (PR #555)
• iOS (PR #555)
• .NET

The following payload will break the UWP parser

{
   "type":"AdaptiveCard",
   "version":"1.0",
   "body":[
      {
         "type":"ColumnSet",
         "columns":[
            {
               "size":33,
               "items":[
                  {
                     "type":"Image",
                     "url":"https://unsplash.it/64?image=1027",
                     "size":"small",
                     "style":"person"
                  }
               ]
            },
            {
               "size":67,
               "contentVerticalAlignment":"center",
               "items":[
                  {
                     "type":"TextBlock",
                     "text":"Hi,",
                     "size":"large"
                  },
                  {
                     "type":"TextBlock",
                     "text":"MasterHip",
                     "size":"medium",
                     "isSubtle":true
                  }
               ]
            }
         ]
      }
   ]
}

It breaks simply because each column item doesn’t have "type": "Column" specified which is redundant and unnecessary, since ColumnSet’s column property is explicitly an array of Column type… the Web visualizer doesn’t break on this.

[dclaux]

If we think we could have a different type of column in the future, then I vote for “type” being required. Otherwise, omitting “type” when the type is implicit is a good simplification. We don’t have “type”: “Fact” for a fact in a FactSet for instance.

[khouzam]

All works properly.