[Feature request] Add RemoveAction method to PluginManager

[derrickmoeller]

Is your feature request related to a problem? Please describe. I would like to dynamically add and remove actions / properties from my plugin. I am able to handle the properties with the use of AttachDelegate and DetachDelegate, but am not able to do the same with Actions which currently only has AddAction.

Describe the solution you'd like Add RemoveAction to PluginManager, this would align with existing behavior that already exists for delegates.