This is a big one because it’s hard to make these kind of changes
atomic. This changeset reworks the calendar component which is no longer
dependent on bootstrap and vuex.

As a consequence we can remove axios, bootstrap, and vuex because the
calendar was the last remaining part of the code that was still using
them.

refs #127 #140 #261 #279

We now use the more flexible ErrorDetailArray data structure from
@rokoli/bnb which makes it harder to accidentally ignore or miss errors.

refs #257 #258

refs #186

refs #127

refs #127

This refactors the existing state helpers (useCopy and
useUpdatableState) and unifies them to useUpdateBehaviour, useCopy,
useAPIObjectFieldCopy, useRelation and useRelationList. This eliminates
a lot of custom code in the show settings page and unifies the behaviour
of all input fields and save operations making the experience more
consistent and understandable.

It also enables us to show the save-in-progress state and errors that
occurred during updates for all fields along with customizable debounce
and proper v-model support.

We also got rid of the remaining uses of useSelectedShow. The show
settings page still made use of it despite using a route that
provides the relevant show that should be edited.

refs #182

refs #146

refs #127

refs #121

refs #127

API object attribute names are now:

1. camelCased (#164)
2. use Id / Ids suffix for object references (#172)