Add plateau.v1 schedule

[danieldk]

Description

This schedule yields values from the wrapped schedule, exponentially scaled by the number of times optimization has plateaued.

Types of change

Feature

Checklist

• I confirm that I have the right to submit this contribution under the project's MIT license.
• I ran the tests, and all new and existing tests passed.
• My changes don't require a change to the documentation, or if they do, I've added all required information.