Add additional layer of abstraction between pipeline parameters and module parameters

[brimoor]

It would be nice to have an extra layer of abstraction between module parameters and pipeline parameters. Use cases:

• ability for pipelines to give user-facing names to their parameters that are used by the outside world. Currently, one must use the <module_name>.<parameter_name> syntax in pipeline requests

• ability to perform some manipulation on the user-provided pipeline parameter value to construct the actual module parameter. For example, if the module parameter is a large Config, like, say, eta.core.annotations.AnnotationConfig, and I want to write a pipeline that exposes one of these fields directly to the end user without forcing them to provide an entire AnnotationConfig