Added Experimental Transaction Support for Simple MergeTree Tables

Why it matters

This feature introduces experimental transactional capabilities to simple MergeTree tables to improve data consistency and reliability during inserts and updates. It aims to address the lack of native transaction support in ClickHouse, enhancing atomicity for operations on these tables. However, this feature is highly experimental and not recommended for production use at this stage.

How to use it

Users can enable transaction support on simple MergeTree tables by creating or altering tables with the transaction capability enabled. Since the feature is experimental, it requires configuring the table engine accordingly and testing in a non-production environment. Further operational details should be obtained from the linked GitHub issue and pull request for guidance.