Fix Covers position and target level

[slajob]

Hi, I make some fixes to make it working. I tested it on my KADRILJ roller blind

1. Covers level
   Current_cover_position is a integer so it's not callable.

  File "/workspaces/core/custom_components/dirigera_platform/cover.py", line 95, in current_cover_position
    return self._json_data.attributes.blinds_current_level()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: 'int' object is not callable

2. Covers control attribute
   Changed set_target_position attribute to set_target_level.

  File "/workspaces/core/custom_components/dirigera_platform/cover.py", line 136, in set_cover_position
    print(self._json_data.set_target_position(position))
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'Blind' object has no attribute 'set_target_position'

[sanjoyg]

Thank you @slajob, merged!