Update Engine HydrateAssetPolicies() method for delivery channel model

[tomcrane]

Load full delivery channels information and update Asset model correctly.

Everything in Engine should read the policies populated here rather than fetch again - load the asset, use EF include to populate the actual values of dc policies (e.g., thumb sizes) and then this is used from here on in Engine.

Acceptance Criteria

• On receipt of sync or async method the Engine will fetch Asset from database, whether we receive fully hydrated object or not.
• This fetch includes all policyData that Engine will use for processing.

[tomcrane]

Make sure child properties are populated when you ask the DB for an asset - in this scenario where Engine always needs to know the delivery channels.

[tomcrane]

Compare with current:

protagonist/src/protagonist/Engine/Ingest/AssetIngester.cs

Lines 84 to 98 in 4ff2313

	private async Task HydrateAssetPolicies(Asset asset)
	{
	if (!string.IsNullOrEmpty(asset.ThumbnailPolicy))
	{
	var thumbnailPolicy = await policyRepository.GetThumbnailPolicy(asset.ThumbnailPolicy);
	asset.WithThumbnailPolicy(thumbnailPolicy);
	}
	if (!string.IsNullOrEmpty(asset.ImageOptimisationPolicy))
	{
	var optimisationPolicy =
	await policyRepository.GetImageOptimisationPolicy(asset.ImageOptimisationPolicy, asset.Customer);
	asset.WithImageOptimisationPolicy(optimisationPolicy);
	}
	}

[tomcrane]

This includes updating Engine to use these policies, as well as Elastic Transcoder

[JackLewis-digirati]

This ticket also encompassed the removal of InitialOrigin from an asset