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

The show selection mechanism relied on the parent component to notify
other components, even though the selected show is already part of the
store and all component state can and should be derived from there.

Users should always be able to add new shows even if none have been
created thus far.

refs #97

Up until now we had two different show selectors based on the number of
shows that were available. We now use the same show selector for any
number of shows.

Apart from that shows are now sorted
 1. based on their active state (descending, so inactive last) and
 2. their name (ascending, so A-Z)
in the show selector so it’s easier to find relevant shows.

Other changes:
* title handling has been moved into PageHeader component
* calendar management has been removed and is now handled
  locally in the EmissionManager component
* inactive shows are badged

refs #122

closes #125

It’s nice to be able to select a week in the calendar and share it by
simply copying the URL so that another person may view the same week in
their browser.

This was accidentally removed when migrating to fullcalendar v5 in
14a9ff20.