Add O-counter

[WithoutPants]

Adds an "o-counter". This is represented as a 💦 looking icon. When the counter is > 0, then it is included in the scene card:

On the scene details page, I have implemented a button for the counter. My default, it shows the icon and counter value. When clicked, this button increments the counter. If the button is hovered for 1 second, and the counter value > 0, then a popover menu is shown with decrement and reset items:

I need advice as to where to put this button in the scene details page. Below is a screenshot of possible placements:

To me the best here is probably on the tabs line. We could also right-align it:

Another option is overlaying the button on the scene player when the player is moused-over:

The button is not shown in the fullscreen view.

Let me know where you'd like it placed.

TODO:

• add filter for o-counter (<, >, !=, =)
• add button functionality to the scene card (so that you can click the o-counter button from the scene query page)
• add an operation on the scene query page to reset o-counter for selected scenes

[bnkai]

Imho the tabs right align one has a cleaner look.

[WithoutPants]

I've added a filter and I think I'll leave it there for now. Performing other functions on the query page requires more structural changes, so I'll leave it for a future iteration.

[WithoutPants]

Resolves #291

[bnkai]

Works ok.
Just a note for the filter. IS NULL or NOT NULL aren't usefull for the O-Counter since it's NOT NULL always (0 by default)