added Windows 10 implementation for addImpression()

[spacepope]

important:
dotnet/windows-sdk-for-google-analytics#29 is needed to get this working.
Alternatively cloning my fork https://github.com/spacepope/windows-sdk-for-google-analytics and using that native project instead of the current nuget package should work..

[spacepope]

btw, another thing i noticed with enhanced ecommerce in the Windows GA SDK:
for addPromotion() a promotion action is used, which is submitted as parameter "promoa" to GA backend (see https://developers.google.com/analytics/devguides/collection/protocol/v1/parameters#promoa).
On Windows 10 UWP allthough the hit data seem to be valid, the debug endpoint echoes a parameter warning:

{
  "hitParsingResult": [ {
    "valid": true,
    "parserMessage": [ {
      "messageType": "INFO",
      "description": "IP Address from this hit was anonymized to 79.254.134.0.",
      "messageCode": "VALUE_MODIFIED"
    }, {
      "messageType": "WARN",
      "description": "Unrecognized paramteter 'promoa' found. Please see http://goo.gl/a8d4RP#promoa for details.",
      "messageCode": "UNKNOWN_PARAMETER",
      "parameter": "promoa"
    } ],
    "hit": "/debug/collect?aip=1\u0026promo1cr=creative\u0026av=0.0.1.0\u0026an=io.ionic.starter\u0026ec=My Label\u0026v=1\u0026promoa=click\u0026cid=xxxxxxxx\u0026ea=ACTION_VIEW\u0026el=My Category\u0026promo1id=P9999\u0026promo1ps=Pos 1\u0026promo1nm=Test Promotion\u0026tid=UA-xxxxxxx-x\u0026sr=1200x900\u0026t=event\u0026ul=en-US\u0026vp=1200x900\u0026qt=29995"
  } ],
  "parserMessage": [ {
    "messageType": "INFO",
    "description": "Found 1 hit in the request."
  } ]
}

I haven't done anything with enhanced ecommerce before and have no clue, why this warning is replied, as the parameter is transmitted exactly like in the parameter specifications.
Is there any similar warning in the Android implementation?
Can you see, if the hit url parameter for promotion action is formatted the same way?
Does it work anyways?

[victorsosa]

Please check this from the DOCs
see https://developers.google.com/analytics/devguides/collection/protocol/v1/parameters#promoa

Specifies the role of the promotions included in a hit. If a promotion action is not specified, the default promotion action, 'view', is assumed. To measure a user click on a promotion set this to 'promo_click'. For analytics.js the Enhanced Ecommerce plugin must be installed before using this field.