fix: ensure valid block explorer URL for address links (#5061)

## Problem solved

Short description of the bug fixed or feature added

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## PR-Codex overview
This PR focuses on updating the `href` attribute in the `metadata-header.tsx` file to ensure that the URL for the block explorer correctly appends the address, handling cases where the URL may or may not end with a trailing slash.

### Detailed summary
- Modified the `href` attribute to check if `validBlockExplorer.url` ends with a `/`.
- If it does not, a `/` is added before appending `address/${address}`.

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Author: joaquim-verges

apps/dashboard/src/components/custom-contract/contract-header/metadata-header.tsx

@@ -117,7 +117,7 @@ export const MetadataHeader: React.FC<MetadataHeaderProps> = ({
             <BadgeLink
               key={validBlockExplorer.url}
               name={validBlockExplorer.name}
-              href={`${validBlockExplorer.url}/address/${address}`}
+              href={`${validBlockExplorer.url.endsWith("/") ? validBlockExplorer.url : `${validBlockExplorer.url}/`}address/${address}`}
             />
           ))}