improve API naming

[kMutagene]

I suggest we make it absolutely clear that the APIs of DynamicObj/DynObj handles dynamic properties, and should therefore reflect that in the naming of methods.

Examples:

//Current API state
let a = DynamicObj()
a.SetValue("some prop", 42)
a.GetValue("some prop")

a |> DynObj.tryGetTypedValue<int> "some prop"
a |> DynObj.remove "some prop"

//Proposed naming changes
let a = DynamicObj()
a.SetProperty("some prop", 42)
a.GetPropertyValue("some prop")

a |> DynObj.tryGetTypedPropertyValue<int> "some prop"
a |> DynObj.removeProperty "some prop"

cc @HLWeil