Support CycloneDX 1.6.1

[andreas-hilti]

Closes: #368

• Update schema and tests to version 1.6.1
• Fix downgrading of external references
• Add CryptoRefArray in ProtocolProperties
• Change Data in Component to a List
• Fix xml serialization of component (order of elements)

[codeholio]

Should this one also support the change of sensitiveData from string to array?

https://github.com/CycloneDX/specification/blob/d570ffb8956d796585b9574e57598c42ee9de770/schema/bom-1.6.schema.json#L3372 (array)

https://github.com/andreas-hilti/cyclonedx-dotnet-library/blob/bbf8d477b7d99d17e2f8227cd64c5dda1a6e5caf/src/CycloneDX.Core/Models/Data.cs#L86 (string)

[andreas-hilti]

Should this one also support the change of sensitiveData from string to array?

https://github.com/CycloneDX/specification/blob/d570ffb8956d796585b9574e57598c42ee9de770/schema/bom-1.6.schema.json#L3372 (array)

https://github.com/andreas-hilti/cyclonedx-dotnet-library/blob/bbf8d477b7d99d17e2f8227cd64c5dda1a6e5caf/src/CycloneDX.Core/Models/Data.cs#L86 (string)

You are correct that it is wrong, but this is not related to the 1.6.1 schema, thus, I would prefer to handle it in a separate issue/PR.