Resolve "Implement create competition"

client/src/App.test.tsx

client/src/App.tsx

client/src/__mocks__/axios.js

client/src/actions/cities.ts

client/src/actions/competitions.ts

client/src/actions/types.ts

client/src/actions/user.ts

client/src/hooks.ts

client/src/interfaces/AdminLoginData.ts

client/src/interfaces/City.ts

client/src/interfaces/Competition.ts

client/src/interfaces/CompetitionFilterParams.ts

client/src/interfaces/models.ts

client/src/pages/admin/AdminPage.tsx

client/src/pages/admin/components/AddCompetition.tsx

...nt/src/pages/admin/components/CompetitionManager.test.tsx

client/src/pages/admin/components/CompetitionManager.tsx

client/src/pages/admin/components/styled.tsx

client/src/pages/admin/styled.tsx

client/src/pages/login/components/AdminLogin.tsx