Update to allow combined definition of metadata keys to keep and rename

[apetkau]

Issue

Right now, in order to rename and keep metadata keys, the same key must be defined twice:

iridanext {
    output {
        metadata {
            samples {
                keep = ["key1", "key2"]
                rename = [
                    "key1": "New Key 1",
                    "key2": "New Key 2"
                ]
            }
        }
    }
}

This duplicates effort/lines to write.

Suggestion

One suggested change that could be made is to enable the keep keyword to have two behaviours:

• [Existing behaviour]: If keep is passed a list of strings, these are interpreted as a list of metadata keys to keep
• [New behaviour]: If keep is passed a Map, the map keys are interpreted as a list of metadata keys to keep while the values are used to rename those keys.

Example

This would allow you to have only one place where keys to keep are defined (and renaming is also handled in this same definition).

iridanext {
    output {
        metadata {
            samples {
                keep = [
                    "key1": "New Key 1",
                    "key2": "New Key 2"
                ]
            }
        }
    }
}