[FEATURE]: Add support for multiple ACEs per trustee within a single ACL

[fpfuetsch]

Describe the solution you'd like
I would like to be able to configure multiple ACEs for the same trustee (user/group) in the ACL of an object. Currently it is only possible to add/remove permissions to/from an existing ACE of the trustee.

For example it's currently not possible to configure permissions with different inheritance flags for the same trustee as shown here:

drw-rwx---  3 1000  1000  200 Oct 20 15:06 .
 OWNER: user:1000
 GROUP: group:1000
 CONTROL:dacl_auto_inherited,sacl_auto_inherited
 0: user:1234 allow traverse,container_inherit
 1: user:1234 allow dir_gen_read,dir_gen_write,std_write_owner,delete_child,object_inherit

[fpfuetsch]

@anupamaloke could you check if this is possible from the API side? I found this reference which causes doubts for me.