Feature: Authentication Mechanism

Implement the user authentication mechanism, including the login screen, credential verification, and access to the application.

When a user launches the application, they are presented with a login screen.
The user provides their credentials (username and password).
The system verifies the provided credentials against the stored user database.
If the credentials are valid, the user gains access to the viewer's features and patient data.
In the case of invalid credentials, the system displays an appropriate error message and may trigger security measures.

User Data Protection: The authentication mechanism ensures that sensitive patient data is protected by allowing only authorized users to access it. This enhances patient privacy and complies with data protection regulations.
Security Compliance: The feature helps the application comply with security standards and regulations within the healthcare industry, where data security is paramount.
Role-Based Access: The authentication mechanism enables role-based access control (RBAC), ensuring that users can only access features and data relevant to their roles. This prevents unauthorized access to sensitive information.
Privacy and Consent: The feature ensures that only authorized personnel, who have obtained patient consent, can access sensitive medical information, thus protecting patient privacy and consent rights.

Related to User Story #16

1brahimmohamed / Brain-Tumor-Segmentation-GP