[Feature] User's authentication

[mczujowski]

Requirements:

• according to the designs
• user should be only authenticated with Google SSO
• when the user clicks on the "Log in with Google" button, the Google authentication widget is displayed
• the Google widget handles the whole login process
• once the login attempt is successful, the user should be redirected to the CPF dashboard

Tasks:

• [x] #6
• [ ] #7

Link to designs:

Figma Clickable prototype