Fix: InfiniteContainer refresh race condition

Added a guard clause to `refreshImpl` in `InfiniteContainer` to prevent re-entrant calls when a refresh is already in progress. This fixes an issue where rapid pull-to-refresh actions could cause the container's content (specifically when containing a single item) to disappear temporarily due to race conditions during the removal and addition of components.

Also wrapped the user-defined `fetchComponents` call in a try-catch block to ensure the `requestingResults` flag is correctly reset even if an exception occurs, preventing the container from becoming stuck in a loading state.

Author: google-labs-jules[bot]

CodenameOne/src/com/codename1/ui/InfiniteContainer.java

@@ -124,8 +124,17 @@ public void run() {
     }
 
     void refreshImpl() {
+        if (requestingResults) {
+            return;
+        }
         requestingResults = true;
-        Component[] components = fetchComponents(0, amount);
+        Component[] components;
+        try {
+            components = fetchComponents(0, amount);
+        } catch(RuntimeException err) {
+            requestingResults = false;
+            throw err;
+        }
         if (components == null) {
             components = new Component[0];
         }