Rework modal header structure

src/lib/components/Confirm.svelte

@@ -6,6 +6,8 @@
   import Button from "@lib/components/Button.svelte"
   import Spinner from "@lib/components/Spinner.svelte"
   import ModalHeader from "@lib/components/ModalHeader.svelte"
+  import ModalTitle from "@lib/components/ModalTitle.svelte"
+  import ModalSubtitle from "@lib/components/ModalSubtitle.svelte"
   import ModalFooter from "@lib/components/ModalFooter.svelte"
   import Modal from "@lib/components/Modal.svelte"
   import ModalBody from "@lib/components/ModalBody.svelte"
@@ -37,12 +39,8 @@
 <Modal tag="form" onsubmit={preventDefault(tryConfirm)}>
   <ModalBody>
     <ModalHeader>
-      {#snippet title()}
-        <div>{restProps.title || "Are you sure?"}</div>
-      {/snippet}
-      {#snippet info()}
-        <div>{subtitle}</div>
-      {/snippet}
+      <ModalTitle>{restProps.title || "Are you sure?"}</ModalTitle>
+      <ModalSubtitle>{subtitle}</ModalSubtitle>
     </ModalHeader>
     <p class="text-center">{message}</p>
   </ModalBody>