EXT-7511 FIXED Resolved newly reported problems in appearance UI

- Selection top cropping problem reproduces only for some systems and is caused by deeper problems in flatlist, so in this case it was fixed via workaround (increasing of item pad in flatlists) and the cause of it is in new ticket- EXT-7752 (Flatlist selection is a bit different on different systems).

- '+' button now has a 3 px pad from right for consistensy with "wrench" from other items.

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/549/

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branch : product-engine