[WOM-211] Add commandedState and commandedObsState attributes

• Added commandedState attribute to SKABaseDevice and commandedObsState to SKASubarray classes:
  • Expected states updated for all relevant long running commands when their status is changed to 'IN_PROGRESS'.
• Base device test config changed to new ReferenceSkaBaseDevice in order to use command to call existing simulate_fault() method in reference component manager. Fault commands also added to reference subarray and state changed callback updated to perform 'component_obsfault' action.
• Refactored some of the SKASubarray device tests to use less lines by moving common setup parts to functions.
• Updated devcontainer with correct extensions and git auto completion and nano editor.