Add available variables dropdown (#7964)

- Add variable dropdown
- Insert variables on click
- Save variable as `{{stepName.object.myVar}}` and display only `myVar`


https://github.com/user-attachments/assets/9b49e32c-15e6-4b64-9901-0e63664bc3e8

packages/twenty-front/src/modules/ui/input/components/internal/phone/components/PhoneCountryPickerDropdownButton.tsx

@@ -69,7 +69,9 @@ export const PhoneCountryPickerDropdownButton = ({
 
   const [selectedCountry, setSelectedCountry] = useState<Country>();
 
-  const { isDropdownOpen, closeDropdown } = useDropdown('country-picker');
+  const { isDropdownOpen, closeDropdown } = useDropdown(
+    CountryPickerHotkeyScope.CountryPicker,
+  );
 
   const handleChange = (countryCode: string) => {
     onChange(countryCode);