ColumnActionManager uses an explicit 'type' switch

[jkae]

I'm noticing that ColumnActionManager.getFromConfig uses an explicit switch on the json "type" field, and would thus need to be overridden if anyone wanted to create extensions to column actions from a plugin.

Is there any chance that this could be made more generic, perhaps through some sort of registration system like DataManager does for descriptors and providers?

(I could do it at some point)