Fixes#2945
Split the config and rule persistency in 2 attributes, one storing the
persistency as set in Waybar's config, the other one storing the
persistency as set in Hyprland.
It fixes some conflicts between the persistency state of a workspace as
set in Waybar's config and its dynamic state in Hyprland.
It allows to remove a persistent workspace in Waybar if this workspace
is removed from Hyprland and if the workspace is not set as persistent
in Waybar's config.
```
../include/util/date.hpp:34:26: warning: literal operator suffixes not preceded by ‘_’ are reserved for future standardization [-Wliteral-suffix]
34 | constexpr decltype(auto) operator""d(unsigned long long d) noexcept {
```
While we at it, eliminate use of non-portable GCC conditional expression
syntax. There are no significant side-effects that would justify use of
the language extension.
BREAKING CHANGE: gtk-layer-shell is now required and unconditionally
used. The corresponding config option is removed.
As a part of preparation for future versions of GTK, remove an ability
to use wlr-layer-shell directly. The APIs it required were dropped in
GTK4, and with the menus/tooltips positioning issue being practically
unsolvable it doesn't make sense to keep maintaining the code.
We already use it without checking (`<gio/gdesktopappinfo.h>` in
wlr/taskbar), it's a transitive dependency of GTK and it's always
available on Unix platforms.
The `<experimental/filesystem>` and `-lc++experimental` aren't needed
since LLVM 9.0. And since we now require C++20, checking for the
`<filesystem>` support shouldn't be necessary either.
Previously, the only way to select all the module labels was with the
following kind of selector:
```css
.modules-left > widget > label,
.modules-center > widget > label,
.modules-right > widget > label {
/* ... */
}
```
(and a matching block for the `box` containers).
Now, this can be expressed as
```css
label.module, box.module {
/* ... */
}
```
