kafka: refactor kafka to use another library

[cpanato]

What type of PR is this?
/kind cleanup

Any specific area of the project related to this PR?
/area outputs

What this PR does / why we need it:

• Refactor the kafka output to use another go library that does not need to have a C lib installed in the host.
• Update dockerfile to remove the lib dependency
• add missing stats

Tested, in the log below is a container that can consume messages

root@kafka:/# curl -X POST localhost:2801/test

root@kafka:/# kafka-console-consumer --bootstrap-server localhost:9092 --from-beginning --topic to-do-list --property "print.key=true"
null    {"output":"This is a test from falcosidekick","priority":"Debug","rule":"Test rule","time":"2020-12-11T13:13:40Z","output_fields":null}

Which issue(s) this PR fixes:

Fixes #137

Special notes for your reviewer:

/assign @Issif

[poiana]

@cpanato: The label(s) area/outputs cannot be applied, because the repository doesn't have them

In response to this:

What type of PR is this?
/kind cleanup

Any specific area of the project related to this PR?
/area outputs

What this PR does / why we need it:

• Refactor the kafka output to use another go library that does not need to have a C lib installed in the host.
• Update dockerfile to remove the lib dependency
• add missing stats

Tested, in the log below is a container that can consume messages

root@kafka:/# curl -X POST localhost:2801/test

root@kafka:/# kafka-console-consumer --bootstrap-server localhost:9092 --from-beginning --topic to-do-list --property "print.key=true"
null    {"output":"This is a test from falcosidekick","priority":"Debug","rule":"Test rule","time":"2020-12-11T13:13:40Z","output_fields":null}

Which issue(s) this PR fixes:

Fixes #137

Special notes for your reviewer:

/assign @Issif

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[Issif]

👍

[poiana]

LGTM label has been added.

Git tree hash: 73276ec94dac408116f02ffa82d1db94ad30d9e9

[poiana]

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