Change animation frames (#3627)

## Description
- Changes animation frames to be smaller
- Cleans up file names and popup logic

## tests
- Passes local CI

codex-rs/tui/frames/codex/frame_21.txt

@@ -0,0 +1,17 @@
+                                      
+             eeodcddcdcoee            
+          occeeeecxdxcdeeocce         
+        dceeccece     eexcceeco       
+      ocxdcc             eodcodco     
+     oooce             oxoee eeeeo    
+    ocox             occeoo    eeeo   
+    xcxe           e oeooc     edec   
+     ee            ed cxo       x x   
+    x x  ocdddddccc  exocxo    do x   
+    x xe xe      eox   ececxo  ocoo   
+     d co eeccc  ce     cceod oe o    
+     cc dde                 ecc o     
+       ce  eoe          eodcc oe      
+         cde ccccdxxdddccc  oe        
+            cccdceeeeoedcce           
+