* (Qt) Migrate to Qt6
* basic support Qt6 with minimal changes required for compiling
* look `moc` in QT_HOST_LIBEXECS
* (Qt) Backward compatibility with Qt5
assignments for strings longer than 2 chars
- Use strlcpy concatenation instead of strlcat
- Make sure that what remains of iteration of the '_len' variable
for manual char assignment
is done in a safer way so mistakes are less possible
* Add View feature
Add saving of a filter set in the Explore menu into a so called "View" file which then gets listed alongside playlists.
This also adds the ability to filter a category by range in the Explore menu and not just filter on exact matches.
* Menu improvements for explore and views
* Collapse ozone sidebar in view
* Fix problems with the sidebar in explore/view
* Ignore view files in the Qt playlists menu
* Add missing semicolon
* Support downloading thumbnails in views
as deprecated.
* Use fill_pathname_join_special in the vast majority of cases where
we can ensure out_path is a new empty string
* Get rid of some extension concatenation with strlcat where encountered
* Some general cleanups with NULL termination of strings that get immediately
passed to strlcpy/strlcpy-adjacent functions
