write config sorted into config.xml

[kazesberger]

problem: every time one saves the config page of this plugin, the resulting xml got randomly reordered speaking of sid and permission elements. this makes diffing messy in case one wants to have the config.xml in a git repo. solution: i made SortedSets (TreeSet) where needed without touching the actual persistence code.

[KostyaSha]

:+1:

[oleg-nenashev]

The change needs migration tests at least. Just to make sure that the upgrade works correctly

[KostyaSha]

Wouldn't it be possible convert set to treeset only during deserialization?

[darxriggs]

Is there someone still having this pull request in mind?

[mawinter69]

Using TreeSet has also the disadvantage that is has worse performance compared to HashSet. So a TreeSet should only be used when writing the config xml or when generating the CasC yaml