Nextcloud Node: Include optional fields in Folder:List

[psxvoid]

This PR adds the ability to get additional fields for the Folder:List operation to the NextCloud Node.

Before this change the user is able to get from NextCloud Folder:List only default file or folder properties.

After this change the user is able to get any file or folder property for Folder:List operation by specifying fields to include in the "Additional Options" field for Folder:List operation. Those fields are:

1. Comments Unread
2. Contained File Count
3. Contained Folder Count
4. Content Type
5. eTag
6. Favorite
7. File ID
8. File Path
9. Has Preview
10. Last Modified
11. Owner Display Name
12. Permissions
13. Resource Type
14. Share Types
15. Size

Here is how they look:

[CLAassistant]

All committers have signed the CLA.