This commit adds password validation to the User step:
- Moved password validation logic to a separate `checkPasswordValidity` function, returning detailed results (strength and validation state).
- Simplified validation in `PasswordValidatedInput` by using `checkPasswordValidity` results directly.
- Added dynamic password strength indicator showing success or error based on requirements.
- Integrated environment-specific validation messages (e.g., for Azure).
- Improved code separation between presentation and validation for better maintainability.
- Unit tests: Adds tests for invalid passwords, covering both default and Azure cases.
