test: add unit tests for hasValidation logic

[kamja44]

Add complete unit tests for hasValidation covering all rule branches and edge cases

This PR adds unit tests for the hasValidation function.

• Covers all validation rule branches: required, min, max, minLength, maxLength, pattern, and validate
• Tests both truthy and falsy conditions, including:
  • required as string and boolean
  • 0 as falsy input for numeric rules
  • pattern as RegExp or object
  • validate as function or object
• Verifies that mount is required for validation to pass
• Ensures hasValidation returns false when:
  • no validation rule is provided
  • validation values are explicitly falsy (e.g., false, undefined, null)
  • pattern is provided without valueAsDate/valueAsNumber

This improves the reliability of the validation logic by ensuring that all edge cases and possible value combinations are covered. It also eliminates reliance on as any through type-safe test field definitions.