Project restructuring (fixes macOS builds) (#198)

- Create `Include/` folder for all main projects
- Fix some issues here and there (found while moving things)
- All includes are now in `Tactility/` subfolder and must be included with that prefix. This fixes issues with clashing POSIX headers (e.g. `<semaphore.h>` versus Tactility's `Semaphore.h`)

TactilityHeadless/Include/Tactility/service/ServiceRegistry.h

@@ -0,0 +1,59 @@
+#pragma once
+
+#include "ServiceManifest.h"
+#include "Service.h"
+
+#include <memory>
+
+namespace tt::service {
+
+/** Register a service.
+ * @param[in] the service manifest
+ */
+void addService(std::shared_ptr<const ServiceManifest> manifest, bool autoStart = true);
+
+/** Register a service.
+ * @param[in] the service manifest
+ */
+void addService(const ServiceManifest& manifest, bool autoStart = true);
+
+/** Start a service.
+ * @param[in] the service id as defined in its manifest
+ * @return true on success
+ */
+bool startService(const std::string& id);
+
+/** Stop a service.
+ * @param[in] the service id as defined in its manifest
+ * @return true on success or false when service wasn't running.
+ */
+bool stopService(const std::string& id);
+
+/** Find a service manifest by its id.
+ * @param[in] id the id as defined in the manifest
+ * @return the matching manifest or nullptr when it wasn't found
+ */
+std::shared_ptr<const ServiceManifest> _Nullable findManifestId(const std::string& id);
+
+/** Find a ServiceContext by its manifest id.
+ * @param[in] id the id as defined in the manifest
+ * @return the service context or nullptr when it wasn't found
+ */
+std::shared_ptr<ServiceContext> _Nullable findServiceContextById(const std::string& id);
+
+/** Find a Service by its manifest id.
+ * @param[in] id the id as defined in the manifest
+ * @return the service context or nullptr when it wasn't found
+ */
+std::shared_ptr<Service> _Nullable findServiceById(const std::string& id);
+
+/** Find a Service by its manifest id.
+ * @param[in] id the id as defined in the manifest
+ * @return the service context or nullptr when it wasn't found
+ */
+template <typename T>
+std::shared_ptr<T> _Nullable findServiceById(const std::string& id) {
+    return std::static_pointer_cast<T>(findServiceById(id));
+}
+
+} // namespace