Pagination

Key aspects of this MR are:

• A new layout manager is introduced
• Pages always have a fixes number of items (here, 24 per page)
• Number of rows and columns per page changes according to the aspect ratio of the screen
• Icon sizes scale down to fit the available size
• Folder dialogs are paginated and slightly tweaked

There are pending tasks here:

• Scroll on the folder dialog is broken
• BaseAppView, AppDisplay, and FolderView could share a lot more code
• In-grid folder management is broken
• Bugs galore

For ease of design review, some screenshots below:

Folder Dialog

New

• Low-res (1366x768)

• Hi-res (1920x1080)

• Ultrawide (2560x1080)

• Portrait (1080x1920)