removing unused imports, creating a file for global decelaration

src/features/authorization/components/AuthenticationSteps/CompleteSignUp.tsx

@@ -1,6 +1,6 @@
-import { Box, Button, Paper, TextField, Typography } from '@mui/material';
+import { Button, TextField, Typography } from '@mui/material';
 import parsePhoneNumberFromString from 'libphonenumber-js';
-import React, { useRef, useState, type Dispatch } from 'react';
+import { useRef, useState, type Dispatch } from 'react';
 import { useTranslation } from 'react-i18next';
 import { AuthenticationCard } from '../AuthenticationCard';
 import { CountryCodeSelector } from '../CountryCodeSelector';