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_15.txt

@@ -0,0 +1,17 @@
+                                      
+                 cccccxe              
+                eodxxedco             
+               ooxcdexccx             
+               xoe ooooeex            
+              xxdcdexxocex            
+              exxoxxoox  c            
+              xx   xxxxxxox           
+              xxoxxcxxx cox           
+              xxcoocxxxeodx           
+              xexdoxexco ox           
+              xoxxxxex e d            
+              xccoexxeo  d            
+              cxeo oooe de            
+               xexxeeoceo             
+                eeceeeeo              
+                   ee