avro

AVRO-3453: Add GeneratedCodeAttribute to generated code by avrogen (#1605)

* AVRO-3360 Updated XML documentation

* Revert "AVRO-3360 Updated XML documentation"

This reverts commit b8601c072a5083380d30b580804dd0908b8cf4cc.

* AVRO-3453 Add GeneratedCodeAttribute to generated code by avrogen

* Fixed tabs

* Removed using and fully qualified the attribute

* Added global

* Update version display

* Updated way to get version.

* Add assembly for netcore 3.1

* Removed preprocessor

* Simplified readability of GetGeneratedCodeAttribute

* Added tabs

* Added validation step to verify the autogenerated attribute exists

Co-authored-by: Kyle T. Schoonover <Kyle.T.Schoonover@nordstrom.com>