Release v3.1.24

blank and filled now support stringable (#617)

* blank and filled now support stringable

* chore: Add blank and filled functions for stringable support

* feat: Add tests for blank and filled functions with stringable support

* chore: Update Functions.php to support Stringable interface

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Co-authored-by: Deeka Wong <8337659+huangdijia@users.noreply.github.com>