Move serializers to zookeeper-api

[narendly]

Issues

• My PR addresses the following Helix issues and references them in the PR description:

Fixes #631

Description

• Here are some details about my PR, including screenshots of any UI changes:

Some serializer implementations were never moved to zookeeper-api. This commit moves them out of helix-core and into zookeeper-api.

Tests

• The following tests are written for this issue:

No test needed.

• The following is the result of the "mvn test" command on the appropriate module:

[ERROR] Failures:
[ERROR] TestZKCallback.testInvocation:188
[ERROR] TestEnableCompression.testEnableCompressionResource:117 expected: but was:
[ERROR] TestControllerLeadershipChange.testMissingTopStateDurationMonitoring:262 expected: but was:
[ERROR] TestClusterInMaintenanceModeWhenReachingMaxPartition.testDisableCluster:119 expected: but was:
[INFO]
[ERROR] Tests run: 1139, Failures: 4, Errors: 0, Skipped: 0

Run separately:

[INFO] Tests run: 7, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 39.199 s - in TestSuite
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 7, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS

Commits

• My commits all reference appropriate Apache Helix GitHub issues in their subject lines. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Documentation (Optional)

• In case of new functionality, my PR adds documentation in the following wiki page:

(Link the GitHub wiki you added)

Code Quality

• My diff has been formatted using helix-style.xml
  (helix-style-intellij.xml if IntelliJ IDE is used)

[narendly]

This PR is ready to be merged, approved by @dasahcc

Move serializers to zookeeper-api (#1085)

Some serializer implementations (Chained, ByteArray) were never moved to zookeeper-api. This commit moves them out of helix-core and into zookeeper-api.

Note that this might cause older implementations of Helix applications to no longer build. Since this is an API-level change that simply moves the classes, the user can simply update the package path in the import statements and can make it build again.