RFC: Rename OptimizerConfig to OptimizerProps

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

Following up PR #6706, I think the name `OptimizerConfig` no longer make sense because it contains per-query execution state such as query execution start time and alias generator.

### Describe the solution you'd like

I think `OptimizerConfig` trait should be renamed to `OptimizerContext` and the existing `OptimizerContext` which is a concrete class should be renamed to `OptimizerState`.

### Describe alternatives you've considered

Leave it as it is

### Additional context

cc @alamb @jackwener

Start by reviewing PR #6706 and locating the definitions and references for OptimizerConfig and OptimizerContext. The issue's title and requested renames disagree, so confirm the intended naming before changing references; done means the agreed names are applied consistently.

Written by the indexing model from the issue text.