Feature: Add optional commit commit to kafka in s3 plugin

[ansakharov]

Issue
Current implementation: file plugin commits event after written to file, s3 plugin writes zip files to storage.
Desired implementation: file plugin commits event after written to file, s3 plugin writes zip files to storage and commits metadata of upload to kafka.
Feature must be optional.

Solution
Add optional embedding kafka output plugin in s3 plugin and add commitment logic.
Afterwards commits to other sources will be provided.

[andrewmed]

Why S3 plugin needs to write something to another destination? AFAIK convention is that there is one output plugin for one destination

If this PR is not a 2-phase commit we should not be using this term

[ansakharov]

I removed 2pc term to avoid ambiguity.