Configurable Completions & Learning Completions

[FriedrichWeinmann]

It would be good to add two features to PSFramework tab completion:

Configurable

A tab completion where the user can provide tab-completion values (and tooltips/completion menu options).
These are persisted to the user profile.

Learning

A Type Transformation attribute can be used to learn input provided to a parameter.
These could be used to automatically learn inputs for tab completion.

Both configurable & learning options should be combinable and learning should be configurable whether ephemeral or persistent.