This reveals more about the nature of an error instead of just
returning "problems setting volume".

libfmt version 9 broke the API by removing fmt::make_args_checked().

Fixes https://bugs.debian.org/1014543

Since PipeWire 0.3.53, control names can apparently be nulled, leading
to crashes in applications assertion that the string cannot be
nullptr.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1558

This fixes a std::terminate() crash in the CURL storage plugin when
PropfindOperation::OnHeaders() throws an exception after receiving a
non-207 status.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1559

Fixes Android build failure with NDK r25 beta4 because "vulkan_beta.h"
was not found.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1536

`playlist_plugin` blocks use `name` to identify the plugins.

This was an experiment, but I decided I don't need that.

The build has been failing for a week or two because the package lists
in the image are outdated.

strlen() and strcpy() are provided by the <string.h> and <cstring>
headers (as functions in global and std namespaces, respectively).

Compilers MAY provide an implementation for either of the functions
without including the extra header but the existence of a declaration
without the header is not assured.

Fixes regression from commit 85f9863e