Add space_type as acceptable field in train API

[ryanbogan]

Description

Adds space_type as an acceptable field in the train API, which is consistent with the documentation

Check List

• [x] New functionality includes testing.
• [x] New functionality has been documented.
• [x] API changes companion pull request created.
• [x] Commits are signed per the DCO using --signoff.
• [x] Public documentation issue/PR created.

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