refactor: Deprecate transcript & triggers endpoints and create tests (#29861)

apps/meteor/app/livechat/imports/server/rest/appearance.ts

apps/meteor/app/livechat/imports/server/rest/triggers.ts

apps/meteor/app/livechat/server/api/v1/transcript.ts

apps/meteor/app/livechat/server/methods/discardTranscript.ts

apps/meteor/app/livechat/server/methods/requestTranscript.ts

apps/meteor/app/livechat/server/methods/saveAppearance.ts

apps/meteor/app/livechat/server/methods/saveTrigger.ts

...or/client/views/omnichannel/appearance/AppearancePage.tsx

...teor/client/views/omnichannel/triggers/EditTriggerPage.js

...eteor/client/views/omnichannel/triggers/NewTriggerPage.js

...Header/Omnichannel/QuickActions/hooks/useQuickActions.tsx

apps/meteor/server/models/raw/LivechatRooms.ts

apps/meteor/server/models/raw/LivechatTrigger.ts

apps/meteor/tests/end-to-end/api/livechat/02-appearance.ts

apps/meteor/tests/end-to-end/api/livechat/08-triggers.ts

apps/meteor/tests/end-to-end/api/livechat/11-livechat.ts

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

packages/rest-typings/src/v1/omnichannel.ts