Initial commit for Waybar JACK monitoring module

-DSP load
  -xruns
  -connected/disconnected state
  -only tested with Pipewire so far but should work with JACK2 as well

 On branch dsp
 Changes to be committed:
	modified:   include/factory.hpp
	new file:   include/modules/jack.hpp
	modified:   meson.build
	modified:   meson_options.txt
	modified:   src/factory.cpp
	new file:   src/modules/jack.cpp

include/factory.hpp

@@ -67,6 +67,10 @@
 #include "modules/custom.hpp"
 #include "modules/temperature.hpp"
 
+#ifdef HAVE_LIBJACK
+#include "modules/jack.hpp"
+#endif
+
 namespace waybar {
 
 class Factory {

include/modules/jack.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <fmt/format.h>
+#include <fstream>
+#include <jack/jack.h>
+#include <proc/readproc.h>
+#include "ALabel.hpp"
+#include "util/sleeper_thread.hpp"
+
+namespace waybar::modules {
+
+class JACK : public ALabel {
+ public:
+  JACK(const std::string&, const Json::Value&);
+  ~JACK() = default;
+  auto update() -> void;
+  jack_nframes_t      bufsize_;
+  jack_client_t*      client_;
+  unsigned int        xruns_;
+  std::string         state_;
+
+ private:
+  std::string         JACKState();
+
+  jack_nframes_t      samplerate_;
+  util::SleeperThread thread_;
+};
+
+}  // namespace waybar::modules