Rework modal header structure

src/app/components/LogInBunker.svelte

@@ -13,6 +13,8 @@
   import Modal from "@lib/components/Modal.svelte"
   import ModalBody from "@lib/components/ModalBody.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 BunkerConnect from "@app/components/BunkerConnect.svelte"
   import BunkerUrl from "@app/components/BunkerUrl.svelte"
@@ -125,12 +127,8 @@
 <Modal tag="form" onsubmit={preventDefault(onSubmit)}>
   <ModalBody>
     <ModalHeader>
-      {#snippet title()}
-        <div>Log In with a Signer</div>
-      {/snippet}
-      {#snippet info()}
-        <div>Using a remote signer app helps you keep your keys safe.</div>
-      {/snippet}
+      <ModalTitle>Log In with a Signer</ModalTitle>
+      <ModalSubtitle>Using a remote signer app helps you keep your keys safe.</ModalSubtitle>
     </ModalHeader>
     <div class:hidden={mode !== "bunker"}></div>
     {#if mode === "connect"}