CB-7972 Add cordova-plugin-globalization support for Windows platform

Addressed code-review #2 notes:
* Fixed stringToNumber method bug that it passed number string in locale-specific format instead of en-US which was failing on parsing in JS
* Made common code to belong to Windows' namespace
* Improved poor class namings
* Got rid of prepareArgs in JS wrapper thus avoided redundant serialization/deserialization in Windows version (this has also improved performance)
 ** Reworked GlobalizationImpl to parse single GlobalizationOptions object instead of parsing an array
 ** Added additional required step to wp8 wrapper to extract GlobalizationOptions JSON for GlobalizationImpl
* Separated wp8 and Windows platforms Invoke (Call) logic (got rid of common Invoke (Call) method)
* Made Invoke method to handle all exceptions (not only FormatException) as a GlobalizationError with specified expectedErrorCode
* Updated and extended the docs