Reldens beta.30 update

Coming from Zephyros implementation in this beta I've pushed a lot of fixes to improve the implementation process itself.

Most of the fixed bugs were related to missing basic configurations or fallback contents which I almost never hit because I was used to start all the new implementations using the sample data.

Since the sample data is optional and we could start an implementation by just installing the base required options those fallbacks were required and some of them start to throw errors.

I'm glad I've found and fixed those pretty quickly.

The part that was not fun at all and the most time consuming (an entire extra day on it), was the change to allow the upload of the map files (the JSON and the images) for the rooms on the administration panel.

For start, I'm dealing with an old version of AdminJS, upgrade to the new one is not an easy task (they've made the module only compatible with ESM + React upgrade, etc.). I can't consider the upgrade as option, so I have to deal with some issues on the old version and mostly with the upload plugin, which I had to highly customize.

Long story short, I had to make the admin only allow to upload a single tileset relation per room, which save me to keep dealing with the multiple uploads issues, and at the end it should be the expected if you "optimize" the tilesets using the Tiled Map Optimizer (which will be migrated into the admin as option when you upload a new tileset).