[energidataservice] Backport changes to 4.3.x

[jlaur]

This backports the following pull requests to 4.3.x:

• [energidataservice] Add support for variable spot price resolution #18379
• [energidataservice] Fix DAY_AHEAD_AVAILABLE event #18583
• [energidataservice] Fix DAY_AHEAD_AVAILABLE event #18644
• [energidataservice] Add support for day-ahead dataset with 15-minute resolution #18695

This will hopefully allow the binding to keep working from after September 30th 2025.

I've had the same version running on my production system for a long period.

This is a follow-up to #18695 (comment), since the same conflict as in #18589 reappeared when trying to cherry-pick.

[kaikreuzer]

Thanks for manually backporting these changes!
Could you give the PR a speaking name, so that it is clear what it is about when it turns up in the release notes?

[jlaur]

Could you give the PR a speaking name, so that it is clear what it is about when it turns up in the release notes?

I was thinking to add the patch label to each cherry-picked PR, so that each change would be properly mentioned. Do you see any problems in that?

[kaikreuzer]

Sure, this should work as well, I think. Then let's not put any label on this PR here.