Set gpt-4o as default for OpenAI (#1391)

docker/.env.example

server/.env.example

server/models/systemSettings.js

server/utils/AiProviders/openAi/index.js

server/utils/agents/aibitat/example/beginner-chat.js

server/utils/agents/aibitat/example/blog-post-coding.js

...ents/aibitat/example/websocket/websock-multi-turn-chat.js

server/utils/agents/aibitat/providers/openai.js

server/utils/agents/aibitat/utils/summarize.js

server/utils/agents/index.js

server/utils/helpers/customModels.js