Add support for field formatters

I started with trying to make the UI basically work. Somehow the changes are partically not saved atm. After quite some trial and error I figured that it is related to the ajax reload.

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After re-factoring, it's basically working now. Opened 📌 Make editing CE entity display basically work Active to work over the UI once we are fully done here and things work from a config.

I figured that entity-displays are still quite connect to core field formatters, what conceptually makes no sense in our case. We need to connect them to CE-field-formatters. For doing so, quite some changes were still needed to finish the introduction of CE-field-formatters. Thus, as a first step I worked over the code to make this work.

Created another branch and MR https://git.drupalcode.org/project/custom_elements/-/merge_requests/43 - which contains a first plugin for fields. For now, testing with a single 'timestamp' formatter.

Also, tried fixing the auto formatter, which needs work. It seems we need to improve our auto-processing to actually support a custom name to be given.

added a dedicated issue for auto-formatting: https://www.drupal.org/project/custom_elements/issues/3443794#comment-15... 📌 Add auto-formatter that uses regular processors Active

finished step2 and made things work. Stumbled over quite some things, added lots of todos for them and created issues for 3.x.
Finally, I worked over tests and made them work again. Partially I added new display-ce configs to make things work, so we see them being taken into account.

Also, I had to work over the render pipeline such that it actually renders config first, and fallsback to processors second. Given that we should have the foundation for 3.x with this PR, but need to work through all of those smaller todos in follow-ups.

Automatically closed - issue fixed for 2 weeks with no activity.