build system and module refactoring + simple histogram scratch (#20)

* scratch adding histogram to image views

Histograms should come from some sort of histogram service. This is
currently just a POC.

* custom logger implementation w/o spdlog

* missing cmake file

* fix tests

* use operator<< over direct stream exposure

* rm print header

* add threading test + refactor towards interface libraries

omits the need for =target_include_directories= calls /everywhere/

* rm print header

* rm constexpr

* templated thread_pool

* fix doxyfile

* default enable doc building

* czi reader refactor

* rm erroneous include expression

* clang-format

* single lib include with PUBLIC visibility

* compile imgui stdlib

* clang format

* documentation update

centralize `LogLevelToString` to `ILog.hpp`

update docs and examples

lib/imaging/include/PixelariumImageFactory.hpp

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <memory>
+
+#include "ILog.hpp"
+#include "IPixelariumImage.hpp"
+
+namespace pixelarium::imaging
+{
+constexpr pixelarium::imaging::ImageFileType ExtensionToType(const std::string& extension)
+{
+    std::string lower_ext{extension};
+    std::ranges::transform(extension, lower_ext.begin(), [](const char c) -> char { return std::tolower(c); });
+
+    if (lower_ext == ".jpg" || lower_ext == ".jpeg")
+    {
+        return pixelarium::imaging::ImageFileType::kJpg;
+    }
+    if (lower_ext == ".png")
+    {
+        return pixelarium::imaging::ImageFileType::kPng;
+    }
+    if (lower_ext == ".czi")
+    {
+        return pixelarium::imaging::ImageFileType::kCzi;
+    }
+    if (lower_ext == ".tiff" || lower_ext == ".tif")
+    {
+        return pixelarium::imaging::ImageFileType::kTiff;
+    }
+
+    return pixelarium::imaging::ImageFileType::kUnknown;
+}
+
+/// @brief Factory for instantiating implementations of IPixelariumImage based on the given file type.
+class PixelariumImageFactory
+{
+    using Log = utils::log::ILog;
+
+   public:
+    static std::unique_ptr<IPixelariumImageCvMat> CreateImage(const std::string& uri, const Log& log);
+};
+}  // namespace pixelarium::imaging