Added validation around pwd_secure_complexity

[marcusmoore]

Description

This PR adds a small amount of validation around the pwd_secure_complexity field when updating settings to ensure unexpected data is not stored.

This will only pop up if users manually change the html of the form but adds a layer of protection:

Type of change

• Bug fix (non-breaking change which fixes an issue)

[shortcut-integration]

This pull request has been linked to Shortcut Story #25004: Add validation around pwd_secure_complexity field.

[what-the-diff]

PR Summary

• Introduction of Validation Rules in Settings Controller
  The code now includes additional validation rules within the Settings controller. This simply means that the system is becoming smarter at checking data to ensure it's correct before processing it.

• Improved Security Field Validation
  In the same controller, there's been extra validation added precisely for the field pwd_secure_complexity, responsible for password complexity. This means our system is now more careful in assessing the strength of the passwords users set, promoting better security.

• General Validation Message Enhanced
  There's been a new general validation message added. That means if an invalid value is entered into a field, the system can notify the user in a more informative way, helping users to input data appropriately.

• Display of Complexity Error Message
  Lastly, an error message has been implemented that will show specifically for the pwd_secure_complexity field. This will help users understand the system's password requirements better, encouraging stronger passwords and thus, better security.

What's evident from these improvements is an emphasis on enhancing password validation, ensuring users create stronger and more secure passwords, and thereby increasing the security of the whole system. It also enhances user interaction due to the improved and more informative error messages.

[snipe]

Nice and straightforward - thanks!