Added add suffix to batch export and made it default.

Used only id with suffix to generate files in batch export to prevent overwriting. Making a copy is default action until ui is ready. This is to prevent silently overwriting files in batch export.

What this fix do?

• First it disable use of filename for batch export as same filename is assigned to every object. Instead we are using object->id.

• It adds suitable suffix to filename ( (id + suffix) .png ) in the form of copy_1, copy_2 to prevent overwriting.

• It sets adding suffix to default. That is there should be no overwriting at all (hopefully).

This is temporary fix related to MR !2835 (closed)