fix PHP 8.1 deprecated warnings with str_replace in _ResourceClient _path_format

[Nicolas-Bouteille]

PHP 8.1 has deprecated passing null as parameters to a lot of core functions such as str_replace.
in JwplatformClient.php _ResourceClient _path_format there are three calls to str_replace with potential null values as parameters.
This is the case when using _ResourceClient->list since it calls _path_format with only three parameters
$this->_path_format($this->_collection_path, $site_id, $this->_resource_name),
which means $resource_id is always null in
protected function _path_format($path, $site_id = null, $resource_name = null, $resource_id = null) {
code needs to be updated to something like:

      if ($site_id) {
        $path = str_replace("{site_id}", $site_id, $path);
      }
      if ($resource_name) {
        $path = str_replace("{resource_name}", $resource_name, $path);
      }
      if ($resource_id) {
        $path = str_replace("{resource_id}", $resource_id, $path);
      }

[Nicolas-Bouteille]

Here is a patch for v2.0.0

Subject: [PATCH] jwplatform-fix-php-8-1-str_replace-deprecated-warnings-path_format
---
Index: src/JwplatformClient.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/JwplatformClient.php b/src/JwplatformClient.php
--- a/src/JwplatformClient.php	(revision 86738a59e08cf9b8123cfb0054784819b78da789)
+++ b/src/JwplatformClient.php	(date 1694697966954)
@@ -121,9 +121,15 @@
     protected $_singular_path = "/v2/{resource_name}/{resource_id}/";
 
     protected function _path_format($path, $site_id = null, $resource_name = null, $resource_id = null) {
-        $path = str_replace("{site_id}", $site_id, $path);
-        $path = str_replace("{resource_name}", $resource_name, $path);
-        $path = str_replace("{resource_id}", $resource_id, $path);
+        if ($site_id) {
+            $path = str_replace("{site_id}", $site_id, $path);
+        }
+        if ($resource_name) {
+            $path = str_replace("{resource_name}", $resource_name, $path);
+        }
+        if ($resource_id) {
+            $path = str_replace("{resource_id}", $resource_id, $path);
+        }
         return $path;
     }