Increase use of W&B, or similar service, for logging and exchanging ideas/results/experiences with different GNN architectures

[asogaard]

Suggested steps:

• [ ] Prepare tutorials / examples leveraging W&B for logging model training and results.
• [ ] Better use the full functionality of W&B (logging training artifacts, such as plots and model files; hyper parameter sweeps; reports; etc.) and promote the value of this functionality.
• [ ] Use W&B projects for benchmarking model architectures and tracking results on common projects.

Relates to #543