Problem component is created even after clicking Cancel

Description

When adding a new Problem component in a unit, clicking Cancel does not prevent the component from being created.

The component still appears in the unit after cancelling the creation/editing flow. This may be expected if the component is created immediately when selected, but the behavior is confusing because Cancel usually implies that the action should be discarded.

I'm opening this issue to confirm whether this is the expected behavior or whether cancelling should remove the newly created component.

Steps to reproduce

1. Go to Course Authoring > Course > Add unit > Add new component.
2. Open a course unit.
3. Select Add New Component.
4. Select Problem.
5. When the problem editor opens, click Cancel instead of saving.
6. Return to the unit page.
7. Check whether the component was created.

Start by reproducing the Course Authoring flow in the issue: add a unit, choose Add New Component, select Problem, then click Cancel. Trace the Problem editor's creation and cancellation entry points to determine when the component is persisted. Confirm with the maintainer whether Cancel should discard the component before changing behavior; done means the agreed cancellation behavior is covered by a regression test.