Add pipeline name to ingest metadata

[peterpramb]

Describe the feature:

When using multiple chained pipelines it would be helpful to provide access to the currently running pipeline's name, something like _ingest.pipeline.

This can be used in error messages or for building up a list of traversed pipelines without the need to hardcode the current name into the pipeline itself (which likely will be forgotten to update when the pipeline is renamed).

[elasticmachine]

Pinging @elastic/es-core-features

[peterpramb]

Additionally, when an exception is propagated to a parent pipeline, the name of the pipeline where the exception originally occured would be useful as well (in the exception handler).

[jbaiera]

@peterpramb In the interest of keeping the issue scope limited, could you open a new issue for including the pipeline name when throwing an exception?

[peterpramb]

Of course, sorry - created #44920.