Feature request: Get inputs to previous steps easily

[samath117]

Just as we can access the output parameters and artifacts of previous steps/tasks using Argo variables, it would also be occasionally useful to be able to access the inputs again.

Format seems clear:

• {{steps.<STEPNAME>.inputs.parameters.<NAME>}}
• {{steps.<STEPNAME>.inputs.artifacts.<NAME>}}
• {{tasks.<TASKNAME>.inputs.parameters.<NAME>}}
• {{tasks.<TASKNAME>.inputs.artifacts.<NAME>}}

[tooptoop4]

isn't this already implemented?

[dberardo-com]

is it possible to refer to the inputs of the entrypoint (the root task/step)?