Use normalized property names for genericmiotstatus

[rytilahti]

This changes the way genericmiotstatus properties are accessed to use normalized names (e.g., light:on = light_on, brush-cleaner:brush-life-level = brush_cleaner_brush_life_level) to make them valid python identifiers, and thus directly accessible using the regular attribute access.

__dir__() is now also implemented for GenericMiotStatus to enable autocompleting these names for easier repling.

Example using mijia.vacuum.v2:

In [7]: for name in sorted(status.property_dict().keys()):
   ...:     print(name)
   ...: 
alarm:alarm
alarm:volume
battery:battery-level
battery:charging-state
brush-cleaner:brush-left-time
brush-cleaner:brush-life-level
clean-record:clean-area
clean-record:clean-time
clean-record:total-clean-area
clean-record:total-clean-count
clean-record:total-clean-time
filter:filter-left-time
filter:filter-life-level
language:language
...

In [8]: status.<tab>
            alarm_alarm                    brush_cleaner_brush_left_time  clean_record_total_clean_area   
            alarm_volume                   brush_cleaner_brush_life_level clean_record_total_clean_count  
            battery_battery_level          clean_record_clean_area        clean_record_total_clean_time  >
            battery_charging_state         clean_record_clean_time        data                            

In [9]: status.clean_record_total_clean_count
Out[9]: 30506