fix: bing language detection api may fail

feat: support http API URL for OpenAI

perf: support custom OpenAI endpoint

feat: add OCR translate command

fix: openai may miss first char, and not use proxy

fix: openai may casuse crash

feat: support OpenAI ChatGPT translation

perf: use user input text instead of selected text when using Fallbac…

…k Command

fix: get bing web translate token failed

perf: try to get system proxy from env first