Item "toString()" and PWX "macro" implementation

Itemdata:

-Added "ToString()" Method to Item-class -> Needs further testing for different itemtypes/variatians. It's supposed to return the same Syntax as "Ingame ctrl+c".
-Added "Copy Itemdata"-button to "SetBuyoutView" -> copy itemdata to clipboard
-moved some objects to "Item" (eg. from Gear) because they are used/necessary for "toString()" -> seems to work fine (since gear inherits item)


PWX/Pricesearch:

-Added Project for PWX-Api
-Implemented simple HTTP-request for the "macro"-URL (should be changed to json, as soon as the api from pwx is online)
-Added "Get Price" to "SetBuyoutView" --> Shows the result as Tooltip on Button

Issues:
Background of tooltip for GetPrice is always transparent. Maybe an issue with another style I cannot find, but tried background, opacity, opacity mask,... Using only border (without tooltip, like search checkbox) could fix the background issue, but then the tooltip cannot be triggered from codebehind...

Bugreports and feedback are always appreciated ;)