test: unify i18next mocks into centralized helpers#2

bar-qodo wants to merge 6 commits intocopilot_bench-100-20260108-copilot_base_test_unify_i18next_mocks_into_centralized_helpers_pr129qodo-benchmark/dify-combined-copilot:copilot_bench-100-20260108-copilot_base_test_unify_i18next_mocks_into_centralized_helpers_pr129from

copilot_bench-100-20260108-copilot_head_test_unify_i18next_mocks_into_centralized_helpers_pr129qodo-benchmark/dify-combined-copilot:copilot_bench-100-20260108-copilot_head_test_unify_i18next_mocks_into_centralized_helpers_pr129Copy head branch name to clipboard