ui/v1.0.0-alpha.1: feat(front): add search to the language picker (#22095)

What Adds a search bar to the Settings → Experience → Language picker, and makes languages searchable across languages. Each option is matched against: its displayed label (the name in the current UI language) its name in English — typing chinese finds “Chinois — Simplifié” its native name — typing 中文 finds the same option Matching is also accent-insensitive ( francais finds “Français”). How The shared Select already supports search via withSearchInput (used by the currency/country pickers) — the picker just opts in.