[WIP] Fixed emojis return type

[briangtn]

There is a problem with the current return type of github emojis endpoint.
At the moment MiscellaneousClient.GetAllEmojis() try to return this data format:

[
	  {
		"name": "+1",
		"url": "https://github.githubassets.com/images/icons/emoji/unicode/1f44d.png?v8"
	  },
	...
]

But the current github api format is:

{
	"+1": "https://github.githubassets.com/images/icons/emoji/unicode/1f44d.png?v8"
	"-1": "https://github.githubassets.com/images/icons/emoji/unicode/1f44e.png?v8",
	...
}

The consequence is that MiscellaneousClient.GetAllEmojis() currently returns an empty set.
So I've updated octokit in order to use the new Github API response format and fix MiscellaneousClient.GetAllEmojis()

[JonruAlveus]

Hi @briangtn, do you plan to return to this PR would you be happy if it was completed by another contributor?

[JonruAlveus]

Replaced with #2577.