Quick Unlock (PIN/Password) with Security Lockout

### Checks - [x] I have read the Wiki, searched the open issues, and still think this is a new feature. ### Explain the problem clearly and succinctly: Hi, ​I am a regular user of KeePassDX and have also purchased the KeePro version via the Play Store to support the development. I truly appreciate the security and features of this app. ​I would like to suggest a feature that would greatly enhance the user experience, similar to the "Quick Unlock" found in KeePass2Android. ​Proposed Feature: ​Quick Unlock (PIN): An option to set a 6-digit PIN for faster access to the database. ​Security Lockout: If the PIN is entered incorrectly more than 3 times, the app should automatically lock the database and require the full Master Password to unlock it again. ​Why this is needed: This feature is very helpful in scenarios where the phone might be shared with family members or friends for a short duration. It provides a balance between convenience and high security without needing to type a long master password every single time, while still protecting the database from unauthorized "guessing" attempts. ​Since I use the Pro version, I would love to see this added to make the app even more versatile. ​Thank you for your hard work on this excellent project! ​Best regards, Deoraj ### Describe the solution you'd like: ​Quick Unlock (PIN): An option to set a 6-digit PIN for faster access to the database. ​Security Lockout: If the PIN is entered incorrectly more than 3 times, the app should automatically lock the database and require the full Master Password to unlock it again. ### Describe alternatives you've considered: Quick Unlock (PIN/Password): An option to set a 6-digit PIN/Password for faster access to the database. Security Lockout: If the PIN is entered incorrectly more than 3 times, the app should automatically lock the database and require the full Master Password to unlock it again. ### Additional context: _No response_