Log Message:
archivers/arqiver: update to 0.8.0

Main changes:
-Now it's possible to drag all selected items, including directories.
-Added an option for only expanding top level directories when loading archives.
-Whether the option "Fit first column into available width" is checked \ 
or not,
the first header column is expanded to fill the available width.
-Added a workaround for Qt's problem with scrolling to deep non-expanded tree
items.
-Don't show the header without content.
-Resize columns appropriately on expanding/collapsing a directory item.
-Added application/x-xz, application/x-bzip and application/zstd to the
supported extractions by using 7z.
-Show the compressed size prefixed by ≥ if the file size is missing.
-Added cmake support (in addition to qmake).