Add Example of Serialization/Deserialization for CSV

[LeviButcher]

Short summary (3-5 sentences) describing the issue.

Currently, there is no up to date example of how to implement a Custom Formatter to return both CSV Response and Read a CSV request (Using text/csv with Content-Type and Accept headers). My use case for needing this example is for allowing batch updates with a CSV file across multiple entity types. This could be elegantly solved if it was possible to accept a request of text/csv and the server automatically de-serialized it and applied the data to a patch endpoint.

Any guidelines would be appreciated and I'm more then willing to write up the example and place over here: https://github.com/OData/ODataSamples

Assemblies affected

*Which assemblies and versions are known to be affected e.g. OData WebApi lib 6.1.0

Most recent Odata Versions.