Pubmatic bid adapter: support ortb2Imp deals

[patmmccann]

Adding some detail here, a publisher should be able to define a pmp like this https://docs.prebid.org/dev-docs/adunit-reference.html#first-party-data ; not just via your adapter parameters. It is a requirement you support the standard openrtb way of forming a bid request when you provide a parameter. The most frequent publisher complaint about prebid is bidder parameters having redundant implementations of the same information

   code: "test-div",
   mediaTypes: {
       banner: {
           sizes: [[300,250]]
       }
   },
   ortb2Imp: {
            "pmp": {
               "private_auction": 0,
               "deals": [
                   {
                       "id": "5678",
                       "bidfloor": 1.75,
                       "bidfloorcur": "USD",
                       "wseat": [
                           "16"
                       ],
                       "at": 3
                   },
                   {
                       "id": "1234",
                       "bidfloor": 2,
                       "bidfloorcur": "USD",
                       "wseat": [
                           "3539"
                       ],
                       "at": 1
                   },
               .....
   // ...
});`````

@patmmccann I am doing the changes based on your comment, but I do see the same json which I used is also being used by pubmatic adapter. Please check the link: pubmatic
Is prebid enforcing this change for all the adapters to standardize the adUnits?

Originally posted by @skapoorViant in #11864 (comment)

All adapters must support standard locations in addition to their parameters

[pm-harshad-mane]

@patmmccann we agree that All adapters must support standard locations in addition to their parameters.
@kapil-tuptewar is looking into it, will respond soon.

[pm-harshad-mane]

@kapil-tuptewar can you please share update?

[kapil-tuptewar]

@pm-harshad-mane adapter specific changes are done. We are discussing this with server side team, once we get clarity I will raise a PR.