EXT-7165 FIXED panel outfit edit now observes all changes in COF (incl. wearables order changes)

- added observing changes in the COF (based on version changes of the COF category, COF's version is also updated when order of COF items is changed)
- got rid of outfit fetcher, cause the only used outfit is COF which is always in a fetched state
- minor cleanup

Reviewed by Mike Antipov and Neal Orman at https://codereview.productengine.com/secondlife/r/356/

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branch : product-engine