AVRO-2123: Duration logical type Java conversion

[robvadai]

Implementation of http://avro.apache.org/docs/current/spec.html#Duration

Can be used to serialize/deserialize to/from Java POJOs and Generic Fixed type.

Make sure you have checked all steps below.

Jira

• [x] My PR addresses the following Avro Jira issues and references them in the PR title. For example, "AVRO-1234: My Avro PR"
  • https://issues.apache.org/jira/browse/AVRO-2123

Tests

• [x] My PR adds the following unit tests:
• lang/java/avro/src/test/java/org/apache/avro/TestDurationConversion.java

Commits

• [x] My commits all reference Jira issues in their subject lines. In addition, my commits follow the guidelines from "How to write a good git commit message"

Documentation

• [x] In case of new functionality, my PR adds documentation that describes how to use it.
  • All the public functions and the classes in the PR contain Javadoc that explain what it does: existing conversaion don't have Javadoc so I didn't add one. This is considered an internal API IMHO.

[adiroy05]

assign to me

[snuyanzin]

Hi @robvadai i'm looking forward to have that feature in Avro, could you please tell us whether you are going to continue work on it or not?

[opwvhk]

As an alternative to this PR, I've opened #2520. This implements a new Java Time class TimePeriod, that combines functionality of java.time.Period and java.time.Duration. Other than that, the PR is equivalent.

[opwvhk]

Closing, as there is now an alternative implementation.