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 #127

refs #182

refs #191

refs #181

This refactor includes a bulk of the changes discussed in #181. It
removes the existing navbar and replaces it with a sidebar instead. This
leaves us more room for context-aware navigation options and other
information that is relevant to users.

Additionally, the show management page is now split up into two, the
show episodes management, listing the coming shows/timeslots and the
show’s schedules, and the show basic data page, that contains all mostly
static data for a show and which is usually maintained by
administrators.

refs #181

This control changes the rendering type for the show previews and should
be placed directly next to it.

This change implements a show overview page with two display modes:
table and grid. Shows can be ordered and searched. Other filters are not
(yet) implemented.

refs #101
refs #181

internal note and show owners are both admin-controlled.

refs #146

refs #155

fixes #153

refs #173

refs #151

refs #156

refs #129

refs #154

Users weren’t able to create a time slot in the calendar if the slot
has already begun.

The logic now checks if the start time is later or equal to the start of
the slot of the current time (i.e. current time is 16:37:28, check is
performed against 16:30:00 for a 15 minute calendar slot size). This
prevents users from creating slots in the past but allows them to create
time slots within a slot that has already begun.

If the slot has already begun then the start time of the new time slot
is set to the next available 5 minute slot after the current time. This
means that if the current time is 16:37:28 and one creates a time slot
in the 16:30:00 - 16:45:00 slot window the start time of the new time
slot is set to 16:40:00.

fixes #167

fixes #151

API object attribute names are now:

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

refs #89

We’ve decided to move the show selector into the navbar because the
selected show is the primary state of the dashboard from which almost
all other state is derived.

Apart from that we now have support for filtering the list based on
active and inactive shows (and possible other criteria in the future) as
it was suggested in #122.

The playlist data is only available for the currently selected show. Any
playlists used in other shows will not be available and we should
gracefully handle that.

This is a quick fix to address #132. A more permanent and helpful
resolution is outlined in #135 and #136.

Auto-formatters can’t know if we rely on any special white-space
handling in our code, so they take the safe route and assume we do.

In this case we don’t, so we can apply formatting that looks a little
more sensible.

This re-implements the auth store with pinia.

Other notable changes:
* the OIDC client configuration and setup is now part of
  separate module that can be included by the OIDC callback routes
  and ensures that we always use the same OIDC client configuration.
* Authorization headers for the steering and tank REST APIs are now
  set with an axios interceptor instead of specifying them for each
  API store action.

refs #127