Close popup & create side menu for privacy policy

Description

Fixes and closes #132

Changelog

• Simplify open/close popup workflow
• Create side item for displaying the privacy policy popup
• Replace ngx-cookie-consent library by a custom mat-dialog for accessibility to the popup

How to test

• Launch visiomanager frontend (it is sufficient)
• Verify that the popup is displayed
• Whatever the choice, verify that the popup is totally disappearing
• Use side item for displaying popup again
• Test page refresh