Provide a way to access generated alias from `YawnCompilationContext` during projection compilation

[luanpotter]

For user-defined custom projection, the user might want to access the alias that was awarded to different tables to compose their SQL.

We can provide that via the YawnCompilationContext to the custom YawnQueryProjection.

[lamkavan-faire]

@lamkavan-faire Tagging myself here so that I can be notified of the progress.

[luanpotter]

Note: this might most likely be impossible with the Hibernate Criteria API.