Upstream new Places icons and 256px size by Ken Vermette

This addresses some of the feedback in the comments of !189 (comment 394335) in the hope to merge this work in Plasma 6. Current status:

New places icons in the Blue Ocean icon refresh. Only targets full-colour icons.

• 558 new vector icons (not including symlinks)
• Adds sizes 128 and 256
• Ensures every icon is available at every size
• Adds more locations including nextcloud, add, signed, and search.
• Adds open variants to all coloured folders
• desktop-type icons, the trash icon, and the start-here icons are now also adaptive. Most folders adaptive.