Turn ad sizes into config entities

We should call these "ad placements" or something like this perhaps, so that the site owner can decide how to use it with more flexibility.

Ad placements can this way be either created just by size, e.g. "Rectangle" or can even be more precise for a region, like "Content area rectangle".

They should therefore have a human-readable label and a machine name. The ad placement can be selected in the ad block (eventually multi-value) and in the ad to publish there (eventually multi-value).

Guess this makes sense as next step, but we should first ensure we have a valid concept.

@anybody and I have now established the concept that we want to implement, and I will do that here.

One lingering issue that I still encounter here is that, for some reason, the parameters sent over from the JS to the Controller on the page do not contain the “placement” value; even though they definitely should after some thorough checking on my side. BUT this only happens when you are admin for another reason? This baffles me quite a bit.

@anybody or @grevil, would you mind taking a look at that?
Apart from that bug, all features are implemented here.

@lrwebks commented!

Before merging this, I need to test it myself as soon as I have the time.

@lrwebks you forgot to modify the database scheme in the update hook, leading to the following error:

Drupal\Core\Entity\Query\QueryException: 'placement' not found in Drupal\Core\Entity\Query\Sql\Tables->ensureEntityTable() (line 373 of core/lib/Drupal/Core/Entity/Query/Sql/Tables.php).

Ok, fixed the update hook and tested, works as expected now! Continuing my review.

Note, that this clears the revision data for "placement" (previously named size), but I really don't want to waste any more time on this 😅

FYI, nice for our Snippet collection:
https://www.drupal.org/docs/drupal-apis/update-api/updating-entities-and... →
https://www.drupal.org/node/2554097 →

Ok, I forgot that by default the revisions are being used for the entity to be displayed, so we actually need to include that in the update hook as well.

Ok, this should do the trick. I will test it tommorow.

Yea, works great. Now to the final issue, pointed out in #7

I can not reproduce #7. When logged in as admin, I can see the ad and "placement" is part of the response data:

@grevil makes sense to me, I couldn't really see a reason for this unexpected behavioru. I'd be fine to assume it's a special bug in @lrwebks's environment... Not worth deeper checks for now?

Alright, everything else works great and as expected! Please review new adjustments @anybody.

@anybody yea probably a browser cache issue, since "placement" did not exist before.

Great!