Resolve "Decouple exports and Sessions Home"

Closes #148

I guess it helps to review this MR commit by commit.

ItemActionId

I introduced ItemActionId for the reason, that I was not able to filter out a globally provided ItemAction by role, as we wanted to show another ItemAction with same role - And there was no functionality to filter globally provided ItemActions - only Actions. I felt it would be annoying to filter all global ItemActions to add them to a list to ignore the globally provided ItemActions. Therefore I introduced the ItemActionId which allows us to filter the ItemActions and allows us to define an order as I personally feel like the order should be decided in the "frontend" and not the "backend" (which is basically the same here, but I wanted more explicitness and more flexibility)

The latter we can revert quite easily.