Add XML fragments to reqif objects when deserializing

[samatstariongroup]

Prerequisites

• [x] I have written a descriptive issue title
• [x] I have verified that I am running the latest version of the ReqIFSharp
• [x] I have searched open and closed issues to ensure it has not already been reported

Description

When a ReqIF object is deserialized, add the XML fragment that represented the object in the ReqIf file. This functionality shall be initialize don request when deserializing as to not incur the memory overhead when this is not requested by the API user

Steps to Reproduce

NA

System Configuration

• ReqIFSharp version:
  • [x] ReqIFSharp: 5.0.0-rc4
  • [ ] Other:
• Environment (Operating system, version and so on):
• .NET Framework version:
• Additional information: