fix: parsing events with empty property names

[tustanivsky]

When fetching Sentry events, the API may return JSON with empty property names causing its conversion to fail and return raw strings instead of parsed objects.

Here's an example non-fatal Unreal event with the following empty properties:

"_meta":{
  "debug_meta":{
    "images":{
      "98":{"debug_id":{"":{"err":["missing_attribute"]}}},
      "99":{"debug_id":{"":{"err":["missing_attribute"]}}}
    }
  }
}

Related to getsentry/sentry-unreal#1127 where this issue originally came up. Unreal SDK currently relies on its custom Get-SentryTestEvent implementation which includes a check for empty property names.

[vaind]

The problem is in the use of Invoke-RestMethod - I think we should parse manually: #12

[tustanivsky]

Closing this in favor of #12