Introduce Error Enum to node-fetch

[lautarodragan]

Creating this issue to track the work done, even though part of the work will be done in another repo.

node/src/Helpers/FetchError.ts

Lines 3 to 13 in 7b67598

	// TODO: make PR to node-fetch with this enum
	export enum FetchErrorType {
	RequestTimeout = 'request-timeout',
	BodyTimeout = 'body-timeout',
	System = 'system',
	NoRedirect = 'no-redirect',
	MaxRedirect = 'max-redirect',
	UnsupportedRedirect = 'unsupported-redirect',
	MaxSize = 'max-size',
	InvalidJson = 'invalid-json',
	}

Will also need to delete the enum from our code base and import node-fetch's one if the PR gets accepted and published.

Will try and tackle this one next Friday, as it's not immediately critical to our progress but something I'd like to see.