[Feature] Admin-Controlled User Group Creation

[sinamics]

• New admin section to create new groups.
• New UserGroup db table, one-to-many relationship between the UserGroup and Users
• Implement user assignment to groups in user table.
• Default group assignment feature for new users registering on the platform.
• Validation checks to prevent deletion of groups with active users.
• User table pagination with search
• Translations

resolves #80