Gerneric image codec abstraction init (#6)

* remove raw pointer from resource manager

* towards generic images

* 💅 and pin libCZI module

* remove raw pointer from resource manager

* towards generic images

* fix rendering

* fix rendering

* fix unit tests

* fix pipeline

* fix gcc build

* re-enable tests

* add czi impl

* remove resource button

* refactor user code app to being a "default app"

* ui resources

* missing lib?

* init czi render support

* typos

lib/imaging/impl/PixelariumPng.hpp

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <stdexcept>
+#include <string>
+
+#include "../IPixelariumImage.hpp"
+
+namespace pixelarium::imaging
+{
+class PixelariumPng : public IPixelariumImage
+{
+   public:
+    explicit PixelariumPng(const std::string& url);
+
+    // IPixelariumImage member implementations
+   public:
+    std::optional<std::unique_ptr<cv::Mat>> TryGetImage() override;
+
+    std::optional<std::unique_ptr<cv::Mat>> TryGetImage(const IImageQuery&) override
+    {
+        // ToDo: proper error
+        throw std::runtime_error("Not possible with png.");
+    }
+
+    std::string Name() const noexcept override
+    {
+        if (!this->uri_.empty())
+        {
+            return this->uri_.filename().string();
+        }
+
+        return {};
+    }
+
+    std::filesystem::path Uri() const noexcept override
+    {
+        return this->uri_.string();
+    }
+
+    bool Empty() const noexcept override { return this->is_empty_; }
+
+   public:
+    const static ImageFileType type_{ImageFileType::PNG};
+
+   private:
+    // this should be set by each image getter
+    // after a new cv::Mat could be instantiated
+    bool is_empty_{true};
+};
+}  // namespace pixelarium::imaging