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/utilities/include/PixelariumLogger.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <memory>
+#include <mutex>
+#include <string>
+
+#include "ILog.hpp"
+
+namespace pixelarium::utils::log
+{
+class PixelariumLogger : public ILog
+{
+   private:
+    struct LogStream;
+
+   public:
+    explicit PixelariumLogger(const std::string& name, const std::string& file_sink);
+    ~PixelariumLogger();
+
+    void Info(const std::string& msg) const override { this->Write(LogLevel::kInfo, msg); }
+    void Debug(const std::string& msg) const override { this->Write(LogLevel::kDebug, msg); }
+    void Warn(const std::string& msg) const override { this->Write(LogLevel::kWarn, msg); }
+    void Error(const std::string& msg) const override { this->Write(LogLevel::kError, msg); }
+    void ChangeLevel(LogLevel lvl) const override { this->level_ = lvl; }
+
+   private:
+    void Write(LogLevel, const std::string&) const;
+
+   private:
+    std::mutex mutable mutex_;
+    std::string name_;
+    std::string file_sink_;
+    std::unique_ptr<LogStream> log_stream_{};
+    LogLevel mutable level_{LogLevel::kDebug};
+};
+}  // namespace pixelarium::utils::log