Prebid.js 7: update pbsBidAdapter to use imp.ext.prebid.bidder.BIDDER

[bretg]

Type of issue

refactoring

Description

Some time back, the Prebid Server committee moved the ortb2 location of bidder parameters from imp[].ext.BIDDER to imp[].ext.prebid.bidder.BIDDER. This was covered in prebid/prebid-server#1478

We would like to move Prebid.js to utilize this new location in version 7 in the pbsBidAdapter

[dgirardi]

This does not look like a breaking change to me; it should be entirely invisible to everything except the PBS adapter. But, does the server advertise support for the new location? Or can we assume that every PBS instance now understands it?

[patmmccann]

Or can we assume that every PBS instance now understands it?

Known host companies now understand it, but old version of PBS may not, and we're not sure how many exist.

[patmmccann]

Code to fix appears to be here

Prebid.js/modules/prebidServerBidAdapter/index.js

Line 713 in 2f33e7d

const ext = adUnit.bids.reduce((acc, bid) => {