Convert `DurationPicker.vue` component to TS

[MilosPaunovic]

We need kestra/ui/src/components/inputs/DurationPicker.vue component converted to TypeScript with the use of Composition API.

<script setup lang="ts">
   // Converted code here
</script>

[MilosPaunovic]

Hi @gauravarora, thank you so much for opening a PR for this, it's really appreciated! 🚀

If you add a comment here, I'll be able to assign you to the issue; otherwise, I cannot due to GitHub's privacy policies.

[gauravarora]

Oh, did not know that.