feat(engine): add JSON as output format for --list/--list_events

[legobrick]

• Added support of the JSON format
• Refactored field and events formatting using the strategy pattern

What type of PR is this?

Uncomment one (or more) /kind <> lines:

/kind bug

/kind cleanup

/kind design

/kind documentation

/kind failing-test

/kind feature

/kind release

Any specific area of the project related to this PR?

Uncomment one (or more) /area <> lines:

/area build

/area engine

/area tests

/area proposals

/area CI

What this PR does / why we need it: Implements support for printing fields and events in JSON. This allows processing and storing them to build a more consolidated repository of those, to fuel side-artifacts like documentation, autocompletion and others, being able to support also plugins and being able to better address versioning, by storing a field definition per-version and computing a multi-version field table.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer: follows the work in falcosecurity/libs#2837

Does this PR introduce a user-facing change?: YES

feat(engine): --markdown has been deprecated in favor of --format, adding the support of json as alternative to markdown and string

[poiana]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: legobrick
Once this PR has been reviewed and has the lgtm label, please assign ekoops for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[github-actions]

This PR may bring feature or behavior changes in the Falco engine and may require the engine version to be bumped.

Please double check userspace/engine/falco_engine_version.h file. See versioning for FALCO_ENGINE_VERSION.

/hold

[leogr]

Hey @legobrick

Thanks for this effort!

First of all, to address the failing CI checks, we need to bump libs. We are doing this on #3799. Let's wait for it, and then rebase, please.

Also, I just found minor issues. Otherwise, SGTM. See my suggestions below.

Finally, the clang-format check is failing on the new code (alignment in field_formatter.h, line wrapping in falco_engine.h, and options.cpp). Please fix it or use the pre-commit hook.

[legobrick]

Hey @legobrick

Thanks for this effort!

First of all, to address the failing CI checks, we need to bump libs. We are doing this on #3799. Let's wait for it, and then rebase, please.

Also, I just found minor issues. Otherwise, SGTM. See my suggestions below.

Finally, the clang-format check is failing on the new code (alignment in field_formatter.h, line wrapping in falco_engine.h, and options.cpp). Please fix it or use the pre-commit hook.

Thanks for the review @leogr, comments should be all addressed and the PR has been rebased