feat(config): config class added

At many points in the code we may want configurable options, the Config class usses a yaml file to make this easy. It also allows for namespace references "opac:lowtemp:file" etc...

src/config/meson.build

@@ -0,0 +1,26 @@
+# Define the library
+config_sources = files(
+  'private/config.cpp',
+)
+
+config_headers = files(
+    'public/config.h'
+)
+
+# Define the libconfig library so it can be linked against by other parts of the build system
+libconfig = static_library('config',
+    config_sources, 
+    include_directories: include_directories('public'),
+    cpp_args: ['-fvisibility=default'],
+    dependencies: [yaml_cpp_dep],
+    install : true)
+
+config_dep = declare_dependency(
+    include_directories: include_directories('public'),
+    link_with: libconfig,
+    sources: config_sources,
+    dependencies: [yaml_cpp_dep],
+)
+
+# Make headers accessible
+install_headers(config_headers, subdir : '4DSSE/config')