Source file organization

[TrigamDev]

Currently, I find the source files of TagStudio (at least in the Qt section) to be very unorganized. They're mainly sorted into the top-level categories of views, controllers, models, and mixed, along with a handful of misc categories, and that's about it. This makes it fairly difficult to find what file you're looking for.

I probably should've opened a discussion before doing so, but in some of my refactor PRs (#1186, #1190, #1217), I've been implementing some more structured organization (this can be reverted if requested).

Here's an organization proposal based on my previous PRs:
(note: currently only includes the files organized in said PRs)

• views
  • preview_panel
    • fields
      • field_container.py
      • field_widget.py
      • tag_box_widget_box.py
      • color_box_widget_box.py
      • text_field_widget.py
    • attributes
      • file_attributes_view.py
      • file_property_widget.py
      • extension_and_size_property_widget.py
      • dimension_property_widget.py
      • duration_property_widget.py
      • font_family_property_widget.py
    • thumbnail
      • preview_thumb_view.py
    • preview_panel_view.py
• controllers
  • preview_panel
    • fields
      • tag_box_controller.py
      • color_box_controller.py
    • attributes
      • file_attributes_controller.py
    • thumbnail
      • preview_thumb_controller.py
    • preview_panel_controller.py
• models
  • preview_panel
    • attributes
      • file_attributes_model.py
• mixed
  • preview_panel
    • thumbnail
      • media_player.py
• previews
  • renderers
    • base_renderer.py
    • audio_renderer.py
    • blender_renderer.py
    • clip_studio_renderer.py
    • ebook_renderer.py
    • exr_image_renderer.py
    • font_renderer.py
    • iwork_renderer.py
    • krita_renderer.py
    • mdp_renderer.py
    • open_doc_renderer.py
    • paint_dot_net_renderer.py
    • pdf_renderer.py
    • powerpoint_renderer.py
    • raster_image_renderer.py
    • raw_image_renderer.py
    • stl_model_renderer.py
    • text_renderer.py
    • vector_image_renderer.py
    • video_renderer.py
    • vtf_renderer.py
  • renderer.py
  • renderer_type.py