Extract the hierarchy macros in a separate template to allow reusing them in the UI

Right now, hierarchy.vm contains both the hierarchy macros and their call, making it impossible to reuse the macros regardless of the other code inside hierarchy.vm.

The proposal is to extract these macros in hierarchy_macros.vm and have hierarchy.vm include it. This way, another template might include hierarchy_macros.vm and call the macros depending on its usecase.