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/slug/frame_20.txt

@@ -0,0 +1,17 @@
+                                      
+              ddtoxxototdd            
+          tcogctdtoooeeddpott         
+        ttgdtpgxpg    egdgotpetd      
+      degdpep           dtteo5poo     
+     de tep           d5gdeedpoeeo    
+     5etep           tppceg5  poxeo   
+    cecte          tp -tpd     toe5   
+    edd5e          ggccegt     exge   
+    e5eectocoooooodtpcddoop    5 eo   
+    pededg 5eeddddeo  poogeoo t5 ee   
+     otdopgggggggpg     otoeete 5o    
+      p dp5t               d5p-e5     
+        oddptxd          tcpecpp      
+          dt--gxtdcctcgxget5pp        
+            eptxdgoddddepgg           
+