feat: add new params to completion snippet

[p-spacek]

What does this PR do?

When object is type anyOf (array: null | string[]) some code completion doesn't work properly.
For example snippets on array it's not working very well.

"anyOf_arrayObj": {
  "anyOf": [
    {
      "type": "array",
      "items": {
        "type": "object"
      }
    },
    {
      "type": "null"
    }
  ],
  "defaultSnippets": [
    {
      "label": "- (array item)",
      "type": "array",
      "suggestionKind": 9,
      "body": {
        "key": ""
      }
    }
  ]
},

Helps also in scenarios where yaml parser doesn't know that parent is array:

anyOf_arrayObj:
  # invoke array completion here

This new parameters can specify:

• type: type of snippet.
• symbolKind: id of symbol that is displayed on completion panel.

This feature probably doesn't solve the cause of the problem. But offers workaround.

What issues does this PR fix or reference?

Completion-Snippet: add parameters to defaultSnippets to specify the type and simbolKind

Is it tested? How?

added unit test

[p-spacek]

done

[evidolob]

@p-spacek Sorry for the delay, there are some tests fail. Could you fix them ASAP? I want to include this PR in to next release.

[coveralls]

Coverage increased (+0.3%) to 77.439% when pulling 9a9a5ad on p-spacek:feat/snippet-paramater-type-kind into 501d75f on redhat-developer:master.

[p-spacek]

@evidolob, I fixed the test.