Improve the stack selector widget

[slemeur]

The goal of this issue is to improve the current stack selector that we have in the Dashboard. At this moment:

• the widget does not scale nicely when the list of stacks is huge
• icons are displayed only for ready-to-go stack
• each stack is represented with a tile, but the tiles does not redraw properly for small resolution
• the search/filter capabilities are
• the tabs experience is not that easy for end-users
• adding a new stack is difficult to find

Here is the proposed solution:

And the behaviors detailled:

[ashumilova]

We can use "Quick Start" instead of "Getting started".

[slemeur]

Good idea ! +1

[slemeur]

As for the first stage of this issue. we will not implement the part with the filter.
This part will definitely be the one which will take the more time - and the experience could also be improved with another ideas that I have.

I'm going to update the issue with mockups without the filters.