Implemented major task EXT-6710(Feature request: Allow drag and drop from...

Implemented major task EXT-6710(Feature request: Allow drag and drop from Inventory panel to Resident Picker)
 - added handling the drag add drop inventory items to resident picker
 - added "Share" verb button to the inventory panel which opens resident picker
 - added "Share" menu item to the individual inventory context menu which acts as verb button
Reviewed by Mike Antipov at https://codereview.productengine.com/secondlife/r/215/

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branch : product-engine