fix(sheets-ui): restore name box range naming flow

[getmateri]

Summary

• allow the formula-bar name box to create workbook-scoped defined names from the current selection on Enter
• reuse the defined-name validation rules in a shared helper so the name box and editor stay aligned
• restore the normal non-editing sheet keyboard state after Enter so arrow-key navigation works immediately

Closes #6704

Test plan

• pnpm vitest run src/views/defined-name/defined-name.utils.spec.ts
• pnpm exec tsc -p tsconfig.json --noEmit
• pnpm exec eslint packages/sheets-ui/src/views/defined-name/DefinedName.tsx packages/sheets-ui/src/views/defined-name/DefinedNameInput.tsx packages/sheets-ui/src/views/defined-name/defined-name.utils.ts packages/sheets-ui/src/views/defined-name/defined-name.utils.spec.ts
• Manual test: create a named cell from the formula-bar name box and confirm arrow-key navigation works immediately after Enter
• Manual test: create a named range from the formula-bar name box and confirm focus returns to the normal sheet state