`ctapipe-apply-models` does not keep order of events

[maxnoe]

Describe the bug

The tables written by ctapipe-apply-models, due to the use of astropy joins, are ordered by obs_id, event_id, not as in the input tables (e.g. /dl1/event/subarray/trigger or /dl2/event/subarray/geometry/HillasReconstructor

This prevents the optimization discussed here #2114

Expected behavior
Keep order of events

[LukasNickel]

Is this what I did here basically?
https://github.com/fact-project/aict-tools/blob/ee091fc933110ff008e32df02ee12a97e412e8b3/aict_tools/io.py#L507

Cant check it in detail right now, but it reminded me on a Problem I had back then

Edit: Probably it's fine to use hstack as in your other pr. The index dance would also slow things down even more

[StFroese]

@maxnoe can this be closed with #2126 ?

[maxnoe]

Yes, fixed.