Split Link header values into different items

[JorgeMucientes]

This PR fixes a crash where the result for URl discoverability returns multiple URLs.

Description

Full context of the crash and proposed fix can be found here: peaMlT-Vb-p2#comment-2323

To Reproduce the crash

Apply this patch

Subject: [PATCH] Split Link header values into different items
---
Index: fluxc/src/main/java/org/wordpress/android/fluxc/network/rest/wpapi/site/SiteWPAPIRestClient.kt
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/fluxc/src/main/java/org/wordpress/android/fluxc/network/rest/wpapi/site/SiteWPAPIRestClient.kt b/fluxc/src/main/java/org/wordpress/android/fluxc/network/rest/wpapi/site/SiteWPAPIRestClient.kt
--- a/fluxc/src/main/java/org/wordpress/android/fluxc/network/rest/wpapi/site/SiteWPAPIRestClient.kt	(revision 9a51a9dfcfdb247e15dc14ad025ddee9e3285ff8)
+++ b/fluxc/src/main/java/org/wordpress/android/fluxc/network/rest/wpapi/site/SiteWPAPIRestClient.kt	(date 1727470975129)
@@ -101,7 +101,7 @@
     private fun discoverApiEndpoint(
         url: String
     ): String {
-        return discoveryWPAPIRestClient.discoverWPAPIBaseURL(url) // discover rest api endpoint
+        return discoveryWPAPIRestClient.discoverWPAPIBaseURL("https://grinderstore.in") // discover rest api endpoint
             ?: WPAPIDiscoveryUtils.buildDefaultRESTBaseUrl(url)
     }
 }

1. Run the FluxC Example app
2. Tap on Sign in & Fetch Sites
3. Log in using site credentials. Any Jurassic ninja site would do.
4. Url API discoverability for WP Rest will be triggered.
5. Wait for 1 second, the app will crash.

Testing

Repeat the steps above but from this branch. The app won't crash.

[hichamboushaba]

Nice work @JorgeMucientes, works great.

[hichamboushaba]

very minor np, we can avoid the instantiation of new Header objects here if we directly return List<String> instead of List<Header> in the request, as we don't need the header itself, we just its value.

[JorgeMucientes]

Good suggestion! Applied!