Rename validation methods for consistency and add numeric validation

- Rename `IsAlphaNumericString` and `IsAlphaString` to `IsAlphaNumeric` and `IsAlpha`.
- Update corresponding tests and error messages for consistency with new method names.
- Add `IsNumeric` method with support for strict and non-strict numeric validation.
- Extend `StringBuilder` with methods for numeric validation, including `IsNumeric` and `RequireNumeric`.
- Update README to reflect new validation method names and behavior.

Corrected inaccuracies in README.md

Add string prefix/suffix removal methods and their corresponding tests

- Implement RemovePrefix, RemoveSuffix, RemovePrefixWithResult, and RemoveSuffixWithResult methods.
- Add implementations for both string utilities and StringBuilder.
- Include comprehensive test cases for all new methods to ensure correctness across various scenarios.

Add validation helper methods and corresponding tests for string oper…

…ations.

-Contains/ContainsIgnoreCase
-ContainsAny/ContainsAnyIgnoreCase
-ContainsAll/ContainsAllIgnoreCase
-HasPrefix/HasSuffix

Update internal package imports to new module path. Upgrade dependenc…

…ies in `go.mod` and `go.sum`.

Merge pull request #1 from bmj2728/feature/strutil

Add initial version of `strutils` library

Enhance README with additional workflow badges for CodeQL, linter/for…

…matter, and testing