NGINX Extra Folders to gui

Add 3 empty folders to the root of nginx (etc/nginx/) called "extra.d", "common.d" and "custom.d"

So they will appear as

/etc/nginx/extra.d/
/etc/nginx/common.d/
/etc/nginx/custom.d/

And add them to the server Nginx GUI editor on ploi, so we can create and edit .conf files inside those folder like we already can do with conf.d folder.

No more is needed. This should be a fairly easy thing to do and it will increase the customization of Nginx a lot.

This is a complement to this request: https://roadmap.ploi.io/items/384-improve-nginx-default-server-adding-a-conf-to-the-end-of-these-lines

And this one https://roadmap.ploi.io/items/383-improve-nginx-customization In fact this last one can be closed with this one, because we can create and manage our own config easily with this 3 extra folders.

I was going to add another request but it is almost similar to this one, so I thought it should be here.

Short: Add another custom empty folder here:

etc/nginx/ploi/DOMAIN/custom/

And do not load that or anything else, but allow to edit and add files from the gui.

Long explanation: Same explanation as above, but this folder will be for sites and not for the whole nginx config.

Another additional folder is needed under the manage nginx for each site. At the moment we have:

nginx/ploi/DOMAIN/before/
nginx/ploi/DOMAIN/server/
nginx/ploi/DOMAIN/after/

All these are included on the nginx default server file. It would be able to have another folder "custom" where we can add other files that are not loaded into the site by default but that we can "include" them one by one if required.