Add direct join algorithm for EmbeddedRocksDB tables

Why it matters

The new direct join algorithm enhances join performance and efficiency when working with EmbeddedRocksDB tables by optimizing how data is accessed and joined, addressing limitations of previous join methods.

How to use it

Users can enable the direct join algorithm by specifying the join algorithm type in their queries or table settings where EmbeddedRocksDB tables are involved. Details are accessible through the related issue and pull request discussions for precise syntax and configuration.