Add the ability to create multi attribute correlation strategy

[cdavernas]

What would you like to be added?

Add the possibility to create a correlation key based on multiple context attributes.

Altough this is already feasible using runtime expressions, it would be a clear quality of life improvement for users who do not want to write needlessly complex expressions to achieve a very common use-case (see additional info).

Proposal(s):

No response

Alternative(s):

No response

Additional info:

As pointed out by @clemensv during the Cloud Shapes presentation of the 02/14/25 in the CNCF Serverless WG, the originating object of a CloudEvents is typically described by a combination of source and subject.

For example, a product Toothpaste sold in a store located in Avenue Louise would be identified by its source, https;//example.store.io/avenue-louise and by its subject colgate-toothpaste.
In CloudShapes, this should result in the composite correlation key https;//example.store.io/avenue-louise/colgate-toothpaste

Community Notes

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