Feature/results calculation user feedback

[bmlancien]

Fixes #95
Fixes #88

I implemented the mockups from #95 without functionality:

• Added calculation description/loading box at the top of the sidebar
  • .panel-item__calc-alert CSS class for normal loading (green)
  • .panel-item__calc-alert.panel-item__calc-alert--error CSS classes if error (red)
• Added chart skeletons placeholders with shimmer animation
• There is now also "Berechnung läuft ..." from last pull from dev, I guess we don't need both the box and this alert at the same time?

The issue from #88 was also a problem here, so I kind of fixed it. I mean kind of, because the arrow of all the tooltips was not placed correctly (you can see this in the screenshot from #88) and I couldn't find a way to fix it, so I decided to simply remove it. I think it works okay. But feel free to check for a solution if you want to. I just didn't want to spend so much time on it as I don't see this as urgent.

@nesnoj

Also, the text should be left-aligned and I'd like to add line breaks - is this easily possible?

• Now the text should be left-aligned
• I added the possibility to use HTML elements in the tooltip:

const tooltipList = [...tooltipTriggerList].map(tooltipTriggerEl => new bootstrap.Tooltip(tooltipTriggerEl, {html: true}))

So it should be possible to add <br>

[nesnoj]

Looks great, thank you!
I can see the elements as described, also HTML works now in tooltips.

@henhuy should give this a check too.
Next step is to wire the progress bar and charts to the rest..

[nesnoj]

Great blinky stuff, cheers!
I commented-out progress bar as it's not wired yet, new issue: #132