[Change Proposal] Add new property to integration to show if their processing can run on Logstash

[jsvd]

Not all Elastic integrations can run their processing on Logstash through the logstash-filter-elastic_integration.
The filter is meant to hide the implementation details of integration processing (Ingest Pipelines in Elasticsearch), but the user is still forced to look up the list of processors used by an integration and compare it with the list of supported processors in the Logstash filter.

It'd be a much better experience for the user to be able to see in the integration page if its processing can be done in Logstash or not. For this purpose the integration page should show an element with this information:

This would require also a change in the package spec to store this new field.
The new metadata element wouldn't require any extra behaviour in the packaging; a cron job would populate this new field in each integration periodically after comparing the ingest pipeline processor and an allow-list encoded in the logstash filter elastic_integration repository.

[lucabelluccini]

Might be tied with #806 (proposal is to put in the specs the types of outputs supported and if the integration can run on EA standalone or not)