Poses : add "active" boolean

[MateoLostanlen]

A camera might have many poses if ti change over times, let's add boolean to pose to tell if it's active or not

[fe51]

In line with #562 (same logic), by default, when retrieving poses, only retrieve active poses (with the option to specify a parameter to retrieve all poses)

Remember to make the change in the /cameras endpoint

Finally, remember to add to the endpoint descriptions that, by default, only active poses are retrieved