This refactors the data handlers into a more standard/understood model-like architecture, to prepare for a new, more robust config system.
It also fixes a problem with creating new Notes and uploading new Photos via the web interface (related to #58).
Finally, it speeds up docker builds by sending in less files, which aren't necessary or will be built anyway.
This is all in preparation to allow building #13 more robustly.
This implements the option to choose directories when uploading files via the Web UI (The most important part of #52).
When you choose a directory, its file and sub-directory structure will be maintained.
Tested with the latest Safari, Firefox, and Chrome.
Additionally, the Deno version was updated, which required some accessibility improvements as well.
This implements generating image thumbnails on the fly via ImageMagick WASM, and tells the browser to cache them for a week, making the loading of photo directories much faster when it has many large images.
Closes#12
