AVRO-3435: Add --version to avrogen tool

[zcsizmadia]

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  • https://issues.apache.org/jira/browse/AVRO-3435
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[zcsizmadia]

Unit tests should be added after #1595 is merged

[KyleSchoonover]

Is the expectation to also support -V? args.Any(a => a is "--version" or "-V") <-- Apparently this is only C# 8
if (args.Contains("--version") || args.Contains("-V") )

[zcsizmadia]

Good catch. I added -V to the cpp avrogen and I intended to add for C# as well.

[zcsizmadia]

@martin-g I added some addition unit tests to make sure that the version returned by avrogen and the version for the main library match and both are SemVer2.0 compliant. Additionally added some tests to make sure that some mandatory attrributes are always defined (e.g. Company, Description ...)