Convert Newtonsoft.Json metadata properties in ConvertFrom-Json - #7308

PR Summary

Use MetadataPropertyHandling.Ignore in JsonSerializerSettings when Deserializing instead of the default (MetadataPropertyHandling.Default). Documentation on this option can be found here and here. Basically Newtonsoft.Json specific metadata properties like $id/$type/$ref are by default read and used by Newtonsoft.Json to deserialize into types, use the same instance for different properties, etc.

ConvertFrom-Json deserializes into the generic type PSCustomObject, I think it doesn't make sense that these specific properties would not be converted as they are part of the json object. This restrict people from using these properties if they are not using Newtonsoft.Json, but even more likely, it restrict them from manipulating the entire raw json data of an object serialized with the library (which is probably what they want to do, otherwise they would be using the library directly to deserialize).

I don't know how "breaking" of a change this is considered to be, I would assume not many people rely on the current behavior, but it is changing with this PR.

Fixes #7307

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