dfpAdServerModule: add ortb fields and ppsj

[ReinoutStevens]

Feature Request

Google recently added support for a plcmt param: https://support.google.com/admanager/answer/10678356#plcmt
Ideally this should be set when generating the DFP URL.

Let's also fill in vpos, vpa, vpmute and ppsj

In the case of ppsj; let's support user.data.ext.segtax we will support segtax 4 and for site. or dooh. or app.content.data we can support segtax 6

https://developers.google.com/interactive-media-ads/docs/sdks/html5/client-side/pps#structuredSignalsTable

[spormeon]

@ReinoutStevens you can set it, just add it to the params: {

[ReinoutStevens]

Sure, but given that that info is also added to the openRTB spec of the adunits it would make sense that Prebid sets this for you? But that might not be in the spirit of Prebid, and prebid should only add the minimal params that are required for it to work.

[spormeon]

there is more than 1 value that can be set?

[patmmccann]

@ReinoutStevens we agree, prebid should set this and more values to construct rich requests

[spormeon]

how do you indicate for vpos? scenario, you have 1 adunit, which feeds both pre-roll and mid-roll & post-roll? I'm guessing these are to be added on the adUnit > mediaTypes > Video, but i dont get why would add dfp/ google attributes ona "prebid" adUnit?

[patmmccann]

@spormeon the publisher might already be setting the field in the ad unit. I don't think we can just figure out, but maybe someone has a way

[spormeon]

if their setting it/ them in the adUnit, they must be passing them to the params of the dfpvideomodule though, or there "useless" on the adUnit, as their "google" attributes and not "prebid/ bidder" attributes. why not just document their use in the dfpvideomodule docs, rather than produce code that "sort of duplicates" things and ending up with "prebid logic" and "dfp logic" on adUnits. It just seems messy to me. Unless there is some "use" i'm completely missing here?

[patmmccann]