Parse a Nexus file as a entry or as a uploaded file.

[RubelMozumder]

Prevent overwriting the schema type from NeXus if nexus will be included a subsection into the archive entry.

This PR add new features:

1. If other areas want the nexus file as file and use the file as a reference to their data path, then nexus file will be under the uploads but not as an entry (E.G. XRD use case by area A).
2. If Nexus subsection is added under the other schema, the new modification will prevent to overwrite the schema name from from the nexus app def (e.g. it would not overwrite the ELNXRDdiffraction schema name.).

[RubelMozumder]

I honestly don't understand why the nexus subsection shall not be filled. You don't loose anything if it's filled and you can still reference the nexus file as a file. Is there any reason why populating the nexus section is necessarily bad?

Nexus subsection will be populated under the other schema whether the nexus file is a nomad entry or just a file, it up to users who wants nexus file as an entry or not. Just giving an option to the users (other areas) what they want.

Some say I would refer the data in the nexus file from the archive entry, why I need extra entry there having the same data.

[lukaspie]

I honestly don't understand why the nexus subsection shall not be filled. You don't loose anything if it's filled and you can still reference the nexus file as a file. Is there any reason why populating the nexus section is necessarily bad?

Nexus subsection will be populated under the other schema whether the nexus file is a nomad entry or just a file, it up to users who wants nexus file as an entry or not. Just giving an option to the users (other areas) what they want.

Some say I would refer the data in the nexus file from the archive entry, why I need extra entry there having the same data.

My opinion would be exactly the other way around, you don't gain anything from not having it filled. But okay, we can add the parameter if necessary.