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/openai/frame_15.txt

@@ -0,0 +1,17 @@
+                                      
+                 ppoooia              
+                apniiaeop             
+               eeionniooi             
+               iea eepeaai            
+              iinonniieoai            
+              niipiieei  o            
+              ii   iiiiiipi           
+              iieiipiii opi           
+              iipppoiiiaeei           
+              iaineinioe ei           
+              ieiiiiai a n            
+              iooeaiinp  n            
+              oinp eeea na            
+               iaiinnepne             
+                naoaaaae              
+                   aa