Enhance password generator user experience

[Vedant43hh]

Description

This PR improves the Password Generator user experience by implementing the requested enhancements.

Changes Made

• Added a password length input field to let users choose the desired password length.
• Added copy buttons for both generated passwords using the Clipboard API.
• Added a descriptive label for the theme toggle to improve usability and accessibility.
• Added input validation for password length.
• Improved the password generator layout with additional styling.

Benefits

• Better user experience.
• Improved accessibility.
• Users can generate passwords of their preferred length.
• Passwords can be copied with a single click.

Related Issue

Fixes #180