Speed up batch ADD and better bechmark

Now I flush only when the file is full and I check the the currently
used file if it is big enough.

So I dont get stat of all files and flush everytime like before

lib/types/out.zig

@@ -1,6 +1,7 @@
 // This file is just to expose what I need to grab
 
 pub const UUID = @import("uuid.zig").UUID;
+pub const Zero = @import("uuid.zig").zero;
 pub const DateTime = @import("date.zig").DateTime;
 pub const OR = @import("uuid.zig").OR;
 pub const AND = @import("uuid.zig").AND;