Use a single mutable location, event, slot, etc, for each unique
resource that keeps track of the local editable client copy and
the server copy of the data contained in it.
This makes it much simpler to update these data structures as I can take
advantage of the v-model bindings in Vue.js and work with the system
instead of against it.
Create a new mutable ClientEntity type and implement ClientUser on top
of it. The mutable concept is intended to replace the immutable concept
used by the ClientSchedule entities as updating immutable types in a
deep interconnected structure is a lot of hassle for little benefit.
