Sort modifiers based on Kotlin conventions

When modifiers aren't in a specific order, the linter suggests to be sorted, ktfmt could sort them.

Start with the Kotlin modifier-ordering conventions referenced in the issue, then trace the ktfmt formatting path for modifier lists. Use representative unsorted declarations to define expected output and verify the formatter applies the convention consistently; done means modifiers are reordered automatically.

Written by the indexing model from the issue text.