The popup (to add a new taxonomy entry in post edit form) has only one field (#term_name), how can I add all the other fields (ACF fields) in this popup?!

The simple answer is that you can’t.
You might be able to build something custom, for example this plugin does something similar with relationship fields https://wordpress.org/plugins/quick-and-easy-post-creation-for-acf-relationship-fields/
But there is nothing built in that will let you do this and there are no plugins for it that I am aware of.
Same need here. It would be great if one day, ACF can do that.