feat: Implement Dub.co for conversion tracking (#16165)

* FEAT: Implement Dub.co for conversion tracking

* add link creation, @vercel/functions

* use refer.cal.com/:username instead of go.cal.com/r/:username

* sale conversion tracking

* add copy referral link

* limit to IS_CALCOM only

* Update yarn.lock

* fix DubAnalytics

* use workaround for isNewUser

* pass req to getOptions

* Update next-auth-options.ts

* fix ts errors

* only show DubAnalytics outside EU

* add Dub Analytics to /signup

* use WEBSITE_URL instead

* on-demand generate links

* add migration

* add check for existing link + change fetch method to poast

* remove refer.cal.com from PoweredByCal

* limit DubAnalytics to /signup only

* simplify generate-referral-link

* restore yarn.lock

* add yarn with dub sdk in

* add yarn with dub sdk in

* yarn

* Update yarn.lock

---------

Co-authored-by: sean <sean@brydon.io>
Co-authored-by: Peer Richelsen <peer@cal.com>

apps/api/v1/pages/api/teams/_post.ts

@@ -215,6 +215,7 @@ const generateTeamCheckoutSession = async ({
     metadata: {
       pendingPaymentTeamId,
       ownerId,
+      dubCustomerId: ownerId, // pass the userId during checkout creation for sales conversion tracking: https://d.to/conversions/stripe
     },
   });