remove ingest-converter

[kaisecheng]

Release notes

Removed the tool Ingest Converter

What does this PR do?

Logstash project has a tool called ingest converter which can do a small set of ingest pipeline processors.
This commit removed ingest converter from the project, including docs and script in /bin

Why is it important/What is the impact to the user?

The tool is no longer relevant given that we have elastic_integration-filter to handle ingest pipeline.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files (and/or docker env variables)
• I have added tests that prove my fix is effective or that my feature works

Author's Checklist

• Logstash can build and run
• DRA job run successfully
• Exhaustive test run successfully

How to test this PR locally

Related issues

• Fix: https://github.com/elastic/ingest-dev/issues/3649

Use cases

Screenshots

Logs

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube

[elasticmachine]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 68c6da3

Failed CI Steps

• 🥼 Integration Tests / part 1
• 🥼 Integration Tests / part 1
• 🥼 Integration Tests / part 1
• 🥼 Integration Tests / part 2
• 🥼 Integration Tests / part 2
• 🥼 IT Persistent Queues / part 1
• 🥼 IT Persistent Queues / part 1
• 🥼 IT Persistent Queues / part 1
• 🥼 IT Persistent Queues / part 2
• 🥼 IT Persistent Queues / part 2
• 🥼 IT Persistent Queues / part 2
• 🥼 x-pack integration
• 🥼 x-pack integration
• 🥼 x-pack integration

[kaisecheng]

exhaustive test is green

[jsvd]

LGTM