Update Mobile Navigation bar css for better usage (#6209)

Closes #5744 
## Description
- Made Navigation Bar fixed in Mobile screens.
- Added `margin-bottom` so, last entries doesn't get hidden.

<img width="340" alt="Screenshot 2024-07-10 at 11 58 50 PM"
src="https://github.com/twentyhq/twenty/assets/91935072/a888fe06-77bf-4368-ac6d-a5d41d591bd0">
<img width="290" alt="Screenshot 2024-07-10 at 11 59 06 PM"
src="https://github.com/twentyhq/twenty/assets/91935072/c1d0c6ed-9178-4132-8b49-7ed39caf3d10">

---------

Co-authored-by: Félix Malfait <felix.malfait@gmail.com>

packages/twenty-front/src/pages/auth/Authorize.tsx

@@ -1,6 +1,6 @@
+import styled from '@emotion/styled';
 import { useEffect, useState } from 'react';
 import { useNavigate, useSearchParams } from 'react-router-dom';
-import styled from '@emotion/styled';
 
 import { AppPath } from '@/types/AppPath';
 import { MainButton } from '@/ui/input/button/components/MainButton';
@@ -14,7 +14,7 @@ const StyledContainer = styled.div`
   display: flex;
   align-items: center;
   flex-direction: column;
-  height: 100vh;
+  height: 100dvh;
   justify-content: center;
   width: 100%;
 `;