Create reproducible script for creating training points

- Training points script. Should test different ways of balancing training points (grid size?) across BGCs, and compare to random assignment of a set number of training points per BGC.

No file, test, or entry point is named. Start by locating the existing training-point and BGC projection workflow, then define the reproducible script inputs and comparison approach. Done means the script compares grid-size balancing methods with random assignment using a fixed number of training points per BGC.

Written by the indexing model from the issue text.