fix: block component block not available yet (#745)

During a regression test after [ctypehub/pull/743](#743), it was found that the "Registration Block" component was showing a broken link after creating a cType from inside the app. This was because the block was still not available and the link required the block number.

Now: 

- The component will direct to the polkadot.js explorer (without querying a specific block) when block number is undefined. 
Reverted: - ~When submitting a cType creation transaction, it will be awaited until it is _InBlock_.~

## Other fix: 
Handle cTypes without a title.

src/components/CTypeDetails/CTypeDetails.astro

@@ -53,7 +53,7 @@ linkToW3N.pathname = web3Name ?? creator;
 
 const linkToBlock = new URL(`https://polkadot.js.org/apps/`);
 linkToBlock.searchParams.set('rpc', blockchainEndpoint);
-linkToBlock.hash = `/explorer/query/${block}`;
+linkToBlock.hash = `/explorer/${block ? 'query/' + block : ''}`;
 ---
 
 <section class={containerStyles.bigContainer}>
@@ -99,9 +99,7 @@ linkToBlock.hash = `/explorer/query/${block}`;
   <fieldset>
     <legend>Registration Block</legend>
 
-    <a href={linkToBlock}>
-      {block}
-    </a>
+    <a href={linkToBlock}>{block}</a>
   </fieldset>
 
   {

src/components/CTypeOverview/CTypeOverview.astro

@@ -16,7 +16,7 @@ const { title, id, description, attestationsCreated, tags } =
 <li class=`${containerStyles.container} container`>
   <h2>
     <a href={generatePath(paths.ctypeDetails, id)} class="title">
-      {title}
+      {title || '∅'}
     </a>
   </h2>