Copper6ssp Bid Adapter: add gvl_id (prebid#5727)

* release adapter Copper6SSP

* fix checks

* fix doc

* add gvl_id

Author: Copper6SSP

dev-docs/bidders/copper6ssp.md

@@ -4,7 +4,8 @@ title: Copper6SSP
 description: Prebid Copper6SSP Bidder Adapter
 biddercode: copper6ssp
 gpp_sids: usstate_all
-tcfeu_supported: false
+gvl_id: 1356
+tcfeu_supported: true
 usp_supported: true
 coppa_supported: true
 schain_supported: true