[Pipelines] Add ability to execute Logstash pipelines

Describe the feature:
Currently, Logstash is able to run on a schedule, but it would be great if there were a way to execute a pipeline through Kibana.
Therefore, executing externally and against the predefined schedule. This applies to Logstash inputs like HTTP/HTTPS and SNMP.

Describe the use case:
Our team continues to aim to leverage ELK over competitors and it seems like executing a poll ad hoc is not supported. Currently, if we want to achieve this, we will have to edit the Logstash pipelines and then run it. The point of this request is to give more power to the users and give them the ability to execute polling for troubleshooting ad hoc.