Add support for merge statements in SQL Server & Fabric

[mattiasthalen]

Microsoft has now added support for merge statements:

https://learn.microsoft.com/en-au/sql/t-sql/statements/merge-transact-sql?view=fabric

How much work would it be to add support for this for both SQL Server and Fabric?

I'm guessing it would be added to the SQL Server engine, and inherited by Fabric & Azure.

[mattiasthalen]

Looks like it's available as opt in via physical_properties in the mssql engine.

Am I correct that we should expose this in Fabric, and remove the inheritance of LogicalMergeMixin?

[georgesittas]

Fixed by #5586