fix: default snippet in array

[rickcowan]

What does this PR do?

Fixes an issue where default snippets where not being entered correctly within an array.

Given the following schema:

{
  "type": "object",
  "properties": {
    "array1": {
      "type": "array",
      "items": {
        "type": "object",
        "defaultSnippets": [
          {
            "label": "My array item",
            "body": { "item1": "$1" }
          }
        ],
        "required": ["thing1"],
        "properties": {
          "thing1": {
            "type": "object",
            "required": ["item1"],
            "properties": {
              "item1": { "type": "string" }
            }
          }
        }
      }
    }
  }
}

When autocomplete is attempted on:

array1:
  - thing1:
      item1: aa
  #cursor here

It previously autocompleted to:

array1:
  - thing1:
      item1: aa

      item1:

After the fix it correctly indents as:

array1:
  - thing1:
      item1: aa
  - item1: 

What issues does this PR fix or reference?

no ref

Is it tested? How?

Manual testing and unit test.

[coveralls]

Coverage decreased (-0.01%) to 83.187% when pulling 3c0e7b5 on jigx-com:fix/main-default-snippet-in-array into e200432 on redhat-developer:main.

[gorkem]

LGTM, thank you for the contribution

[msivasubramaniaan]

Please resolve the conflicts

[p-spacek]

Please resolve the conflicts

Hello, I merged the code and resolved conflicts, there were some problems with the test.
I would suggest reviewing it again?.

I left a little bit related comment here in this PR https://github.com/redhat-developer/yaml-language-server/pull/786/files#r1029764436