Redesign of Manage Grids

[klues]

While redesigning the settings view (#452) I now also thought of redesigning the "Manage Grids" view and also use tabs there.

From this:

To something like this:

The bar at the top with New grid and More could be removed and all the functionalities could be moved to the tabs. All the backup / restore functionalities from the "More" button could be moved to the "Backup / Restore" tab.

The "accumulated phrase options" and "collect element options" (also see issues #180 and #284) probably then should be in the tab "global grid"?!

I'm not going to implement this right away, since I want to focus on finishing #451 and #452 first, but we can already discuss the best solution here, @arasaac-dga @ms-mialingvo.

[arasaac-dga]

We like it the new design for "Manage Grids" page. We understand that "New cell" button will be in All Grids tab, isn't it?

The "accumulated phrase options" and "collect element options" (also see issues #180 and #284) probably then should be in the tab "global grid"?!

Yes. They must be allocated in Global Grid tab due accumulated phrase usaully are placed in Global Grid.

[ms-mialingvo]

On the choose how to start site, there is an info-button with details on the grid set: Author, description, language(s), tags, edit on github, copy direct link to this configuration to clipboard. I can't find that info anymore anywhere after activating a specific grid set. If it's not that I'm just overlooking where it is, that info and links should also be there somewhere in the all grids tab after redesign.

Edit: It's better to also include the license type with a link to creativecommons. So, something like CC BY-NC-SA by [author name]