Implement physical optimizer rule to apply type coercion to physical plans

### Is your feature request related to a problem or challenge?

For DataFusion users who are starting with physical plans rather than logical plans, a physical optimizer rule to apply type coercion to physical plans would be helpful.

See the discussion in https://github.com/apache/datafusion/pull/14283#issuecomment-2614533646 for one example where this would be helpful.

### Describe the solution you'd like

_No response_

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

No file or test is named. Start by reading the discussion in the linked pull request, then trace how physical plans and physical optimizer rules are handled; done means a physical optimizer rule can apply type coercion to physical plans for users who start from them.

Written by the indexing model from the issue text.