Smaato: Change server response type

[Enigo]

We've simplified our server response to make it more ortb-like Backward compatibility is guaranteed server-side

[github-actions[bot]]

Code coverage summary

Note:

• Prebid team doesn't anticipate tests covering code paths that might result in marshal and unmarshal errors

• Coverage summary encompasses all commits leading up to the latest one, 8906df3c6c4bc4127c795ca7984c200f69602af5

  smaato

  Refer here for heat map coverage report

  github.com/prebid/prebid-server/v2/adapters/smaato/banner.go:9:     extractAdmBanner        100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/native.go:14:    extractAdmNative        85.7%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:70:    Builder             100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:79:    MakeRequests            100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:99:    MakeBids            85.3%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:163:   makeIndividualRequests      89.5%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:196:   splitImpressionsByMediaType 100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:226:   makePodRequests         84.6%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:250:   makeRequest         85.7%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:269:   getAdMarkupType         100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:279:   getTTLFromHeaderOrDefault   100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:293:   renderAdMarkup          100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:308:   convertAdMarkupTypeToMediaType  80.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:323:   prepareCommonRequest        100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:337:   prepareIndividualRequest    100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:347:   preparePodRequest       80.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:359:   setUser             95.2%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:402:   setExt              100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:410:   setSite             100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:430:   setApp              100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:437:   setPublisherId          100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:456:   setImpForAdspace        90.9%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:476:   setImpForAdBreak        94.1%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:508:   makeImpExt          90.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:530:   groupImpressionsByPod       100.0%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:550:   buildBidVideo           87.5%
  github.com/prebid/prebid-server/v2/adapters/smaato/smaato.go:570:   extractBidExt           100.0%
  total:                                  (statements)            93.1%