Draft: Redesign the forecasts in horizontal cards

Hi,

Today I present a MR which aims to redesign the daily and hourly forecasts using an horizontal design, within cards. The forecasts are now aligned vertically, in contrary to the previous vertical/horizontal layouting.

For the moment :

• Dynamic style is working
• Flat style is having problems with spacing and background for daily cards
• I haven't made a switch for daily/hourly using a RadioSelector because it is not yet in Kirigami Addons (only (hard?)coded in Itinerary and MarkNote) ; see libraries/kirigami-addons!175 (merged)
• I'm not sure about how to make a scrolling container, because 24 cards is taking a lot of vertical space.

For next MR in that direction, I'll move the info card + astral card into a collapsing menu in the forecast card (like the intermediate stops in Itinerary). But I preferred to do that one separately, because it represents a big changement ; due to many links between items, I was not able to split it more.

Some fewer MRs maybe come later these days, I have some ideas in my mind.

I think I removed most of the comments of old code (I've been using those while developing), but let me know if I forgot some parts.

I'm not able to do better screenshots than my PC's webcam, because the screenshot util is not working in PMo (there is an issue for that ofc). So please ask other reviewers for screenshots.

Hope you'll like it :)