allow auto detect user lang without setting it or login
### Problem to solve 1. login user need to go to setting panel set site ui lang 2. not yet login user, can't change site ui lang ### Intended users 1. people who is not english user ### Further details <!-- Include use cases, benefits, and/or goals (contributes to our vision?) --> ### Proposal <!-- How are we going to solve the problem? Try to include the user journey! https://about.gitlab.com/handbook/journeys/#user-journey --> 1. auto detect browser info and choose lang 2. allow ghost can change site lang ### Permissions and Security <!-- What permissions are required to perform the described actions? Are they consistent with the existing permissions as documented for users, groups, and projects as appropriate? Is the proposed behavior consistent between the UI, API, and other access methods (e.g. email replies)? --> ### Documentation <!-- See the Feature Change Documentation Workflow https://docs.gitlab.com/ee/development/documentation/feature-change-workflow.html Add all known Documentation Requirements here, per https://docs.gitlab.com/ee/development/documentation/feature-change-workflow.html#documentation-requirements --> ### Testing <!-- What risks does this change pose? How might it affect the quality of the product? What additional test coverage or changes to tests will be needed? Will it require cross-browser testing? See the test engineering process for further guidelines: https://about.gitlab.com/handbook/engineering/quality/guidelines/test-engineering/ --> ### What does success look like, and how can we measure that? <!-- Define both the success metrics and acceptance criteria. Note that success metrics indicate the desired business outcomes, while acceptance criteria indicate when the solution is working correctly. If there is no way to measure success, link to an issue that will implement a way to measure this. --> ### Links / references
issue