Implement Dchain Support

[pm-saurabh-narkhede]

#3549

[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, 439bdf19fa1489358cc51aca5bfc384a570c1cc6

pubmatic

Refer here for heat map coverage report

github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:83:	MakeRequests				93.4%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:187:	validateAdSlot				91.3%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:230:	assignBannerSize			100.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:238:	assignBannerWidthAndHeight		100.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:246:	parseImpressionObject			91.3%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:333:	extractPubmaticExtFromRequest		96.7%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:385:	getAlternateBidderCodesFromRequestExt	100.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:403:	addKeywordsToExt			85.7%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:417:	MakeBids				88.9%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:505:	getNativeAdm				90.9%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:527:	getMapFromJSON				100.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:539:	populateFirstPartyDataImpAttributes	100.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:552:	populateAdUnitKey			100.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:567:	populateDctrKey				85.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:617:	getStringArray				100.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:630:	getBidType				100.0%
github.com/prebid/prebid-server/v2/adapters/pubmatic/pubmatic.go:650:	Builder					100.0%
total:									(statements)				92.8%

[bsardo]

Closing this for now as it has been open in a draft state for almost six months. We can always reopen if needed.