Renamed str_fmt_alloc to str_fmt, str_fmt to str_fmt_out, allocator convention enforcement in context

I'm enforcing aprintf it as the default formatter.
I changed up the context allocator assignment to reflect how I've been intending to allocation in startup & platform events vs tick.
Tick uses the frame slab's by default with transient on temp. Startup & platform events use the transient by default & for temp, with any use of the persistent allocator being explicit.

code/sectr/app/screen.odin

@@ -265,7 +265,7 @@ ui_screen_settings_menu :: proc( captures : rawptr = nil ) -> ( should_raise : b
 					else
 					{
 						array_clear( value_str)
-						array_append( & value_str, to_runes(str_fmt_alloc("%v", config.engine_refresh_hz)))
+						array_append( & value_str, to_runes(str_fmt("%v", config.engine_refresh_hz)))
 					}
 					ui_parent(input_box)