feat: use Livechat Contacts as a reference for the MAC limit (#33816)

.changeset/slow-flies-hear.md

...eteor/app/cloud/server/functions/buildRegistrationData.ts

apps/meteor/app/livechat/server/hooks/markRoomResponded.ts

apps/meteor/app/livechat/server/lib/Helper.ts

.../meteor/app/livechat/server/lib/contacts/ContactMerger.ts

.../app/livechat/server/lib/contacts/registerContact.spec.ts

apps/meteor/ee/app/license/server/startup.ts

apps/meteor/tests/end-to-end/api/livechat/09-visitors.ts

apps/meteor/tests/end-to-end/api/livechat/23-mac.ts

...ests/unit/server/livechat/hooks/markRoomResponded.spec.ts

packages/core-typings/src/ILivechatContact.ts

packages/model-typings/src/models/ILivechatContactsModel.ts

packages/model-typings/src/models/ILivechatRoomsModel.ts

packages/model-typings/src/models/ILivechatVisitorsModel.ts

packages/models/src/models/LivechatContacts.ts

packages/models/src/models/LivechatRooms.ts

packages/models/src/models/LivechatVisitors.ts