Added Plugin support (#102)

* Build refactoring and initial plugin support

* Possibly fixed linux / mac build

* Added libdl to libglad build script

* Add glfw to imgui dependencies

* Refactored common functionality into "libimhex" for plugins

* Added plugin loading and example plugin

* Added proper API for creating a custom view and a custom tools entry with plugins

.github/workflows/build.yml

@@ -85,6 +85,7 @@ jobs:
           mingw-w64-${{ matrix.arch }}-polly
           mingw-w64-${{ matrix.arch }}-python
           mingw-w64-${{ matrix.arch }}-freetype
+          mingw-w64-${{ matrix.arch }}-dlfcn
 
     - name: ✋ Build
       run: |