Refactor data validation module for improved modularity and functionality

- Removed the existing `validation.py` file and replaced it with a modular structure, introducing separate files for validation results, field validators, and the base validator class.
- Implemented comprehensive validation functions for common data types, enhancing reusability and maintainability.
- Added a new `__init__.py` to expose the validation utilities, ensuring a clean public interface.
- Created detailed documentation for the validation module, including usage examples and architectural details.
- Introduced extensive unit tests to cover the new validation framework, ensuring reliability and preventing regressions.

These changes enhance the overall architecture of the data validation module, making it more scalable and easier to manage.

tasks/refactor-common-package.md

@@ -38,11 +38,11 @@
   - [x] 2.8 Delete the original `data/common/indicators.py` file.
   - [x] 2.9 Run tests to verify the indicators logic still works as expected.
 
-- [ ] 3.0 Refactor `validation.py` for better modularity.
-  - [ ] 3.1 Create safety net tests for validation module.
-  - [ ] 3.2 Extract common validation logic into separate functions.
-  - [ ] 3.3 Improve error handling and validation messages.
-  - [ ] 3.4 Run tests to verify validation still works as expected.
+- [x] 3.0 Refactor `validation.py` for better modularity.
+  - [x] 3.1 Create safety net tests for validation module.
+  - [x] 3.2 Extract common validation logic into separate functions.
+  - [x] 3.3 Improve error handling and validation messages.
+  - [x] 3.4 Run tests to verify validation still works as expected.
 
 - [ ] 4.0 Refactor `transformation.py` for better modularity.
   - [ ] 4.1 Create safety net tests for transformation module.