Add Hamburger Menu for AdminPanel Sidebar on Mobile Devices.

### Is your feature request related to a problem? Please describe.

We can't keep the AdminPanel sidebar open on mobile devices due to lack of space. So currently there's no way to access the AdminPanel sidebar on mobile devices.

### Describe the solution you'd like

Add a hamburger menu icon (keep the color "yellow", the same as the theme color) to the navbar that will be visible on `mobile devices & admin route only`. When the hamburger icon is clicked, it should open the AdminPanel sidebar in a` side drawer`.

Also, make the "BUSIFY" text of the sidebar responsive for tablet screens(currently seems too small).

### Describe alternatives you've considered

_No response_

### Developer Help

In order to view the admin page as an "Admin" role, you can make a slight change in "frontend/src/store/ authstore.tsx" file:
At line 25 :
`setUser: user => set({
user: {
...user,
role: 'admin',
}
}),`