Added Pulsar IO connector for local files

[david-streamlio]

Motivation

Added a Pulsar IO connector for consuming files from the local filesystem

Modifications

Added a new module to the pulsar-io module that includes the Pulsar file connector and its associated classes & tests

Result

After your change, users will be able to consume files from the local filesystem, and have the contents directly published to a Pulsar topic.

[jiazhai]

rerun java8 tests

[jiazhai]

overall lgtm, But @david-streamlio Seems the ut is flaky: org.apache.pulsar.io.file.FileSourceConfigTests.InvalidBooleanPropertyTest
https://builds.apache.org/job/pulsar_precommit_java8/4711/

[david-streamlio]

@sijie I am not sure why the test fails during testing. I am able to run the test successfully locally using TestNG 6.13.1. Do we use a different version of TestNG on Jenkins?

The error is related to the TestNG regex not matching the expected string, but as you can see from visual inspection that the String should match.

"@test(expectedExceptions = com.fasterxml.jackson.databind.exc.InvalidFormatException.class,
expectedExceptionsMessageRegExp = "Can not deserialize value of type java.lang.Boolean from String .*")

[david-streamlio]

rerun java8 tests

[sijie]

@david-streamlio can you rebase this PR to latest master?