Add custom activities to entities such as orders

[fxmb]

We want to add custom acitvites. e.g. "Delivery Time Changed" to our order activities. It seems that this is not possible? It should be amazing if there was a workflow that lets me define an entity e.g. "order" with an id (ord_abc) and then some object with message and details which I could add to any entity in medusa and call in the backend.

Does this exist? According to the docs and what I saw on discord this does not exist.

Would be extremely helpful, otherwise its impossible to track changes across teams and over time for critical flows. I know I can build this customly but would be much nicer as a core feature