Enhance SortMergeJoinExec by implementing EagerJoinStream for the join

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

For a more maintainable SortMergeJoinExec, we can implement the common logic with EagerJoinStream since it is quite similar to what is done there.

### Describe the solution you'd like

The state machine management of SortMergeJoinExec needs to be updated to align with the EagerJoinStream trait.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

Start by locating SortMergeJoinExec and the EagerJoinStream trait, then compare how their state machines manage join progress. The work is complete when SortMergeJoinExec uses the common EagerJoinStream logic and its state management is aligned with that trait without changing the join's intended behavior.

Written by the indexing model from the issue text.