Rewrite of Sciline's Pipeline

[SimonHeybrock]

Overview

This is a rewrite of Pipeline, as discussed in many places. Please see the rewrite.ipynb notebook for some context.

List of changes

• TypeVars need to be constrained. The new mechanism eagerly inserts duplicate nodes based on this.
• Mechanism to favor most-specialized provider is removed. The last provider being inserted is the one that is used. This may be a pitfall, but otherwise it is never clear if an insert should replace existing providers or not, and may even make it impossible to replace specialized providers with a generic one. The new implementation is very simple, so that is what we do.
• Param table support removed, in favor of map and reduce based on Cyclebane. Not that groupby is not supported yet, but we have never used this in practice.
• Provider input type hints must be unique.
• __setitem__ and __getitem__ can be used to compose more complex graphs, sidestepping the dependency-injection-driven assembly of the base pipeline.

[SimonHeybrock]

Are there more comments here that cannot be done in a follow-up?