Scheduled transition is not saved on node form submit unless you click to the Save button in the new transition item row

Problem/Motivation

If you're familiar with the Drupal multivalue field's, Inline Entity form field's or Paragraph field's UX, then as soon as a new line of valid field values are added to a field, users expect that if you click the node form's Save button on the bottom, the values will be saved.

Steps to reproduce

- open node add or edit form
- fill in required fields
- at the bottom on transitions, click "Schedule a status change"
- set the new state and time for transition but do not click the Save button or cancel link in this new row
- instead click the Save button on the bottom
- open node edit form again and notice that your scheduled transition was not saved because you did not click that little Save button there

Proposed resolution

As soon as a new row is added there, consider saving that data if the state and date setting is valid there. Do not remove anything silently.

Remaining tasks

User interface changes

API changes

Data model changes