Depviz web: click = change Focus + open info box

[moul]

The goal of this issue is to change the current behavior of clicking a card

Today, when you click a card it will open a new tab with the corresponding issue/pr

The new expected behavior is to open an info box with more details + action buttons (including a "view on GitHub" button that will open a new tab)

To make the interface easy to use, the new infobox should stay fixed somewhere on the page, so it's easy to continue navigating in the graph, so:

1. if no card clicked -> the infobox is closed
2. you click a card -> it add a "selected" bold border on the issue + open the infobox on that issue
3. if you just drag and drop the graph, the previous card stay open
4. if you click on another card, then it replaces the infobox content with info for the new issue

┆Issue is synchronized with this Trello card