feat: Add a lint to avoid hardcoded strings

[ShahSomething]

Description

It would be helpful to add a lint that flags hardcoded strings in Dart/Flutter code. Hardcoded strings can make localization and maintenance more difficult, especially in larger apps. A lint to detect these would help enforce best practices and encourage the use of constants, resource files, or localization frameworks like flutter_localizations.

Example

// Bad
Text('Welcome');

// Good
Text(AppStrings.welcome); 

Requirements

• [ ] All CI/CD checks are passing.
• [ ] There is no drop in the test coverage percentage.

Additional Context

No response