Fix T60753: Graph Editor showing cache curves regardless of filters

This commit adds a datablock filtering option for cache files channels,
so that a shot with lots of these in addition to standard animation
(e.g. the Spring production files) don't become bogged down by these.

Furthermore, these channels also respect the "Only Selected" toggle too now.

release/scripts/startup/bl_ui/space_dopesheet.py

@@ -148,6 +148,8 @@ class DopesheetFilterPopoverBase:
             flow.prop(dopesheet, "show_textures", text="Textures")
         if bpy.data.shape_keys:
             flow.prop(dopesheet, "show_shapekeys", text="Shape Keys")
+        if bpy.data.cache_files:
+            flow.prop(dopesheet, "show_cache_files", text="Cache Files")
 
         layout.separator()