build(flake-parts/web): include wasm modules from nix

Previously the `public/loader` directory contained a wasm ES module that
was used for initializing service workers. Instead of including it with
the code it is now built using nix and included in the `static-files`
package.

The mechanism for loading this is also used for the `ui` and `wasm`
crates. The `wasm-modules` attrset copies the files from the derivations
given to it into the `public/wasm/${name}` directory.

The loader files have been removed from the codebase and the html has
been updated to reflect the new directories of the modules.

flake-parts/web.nix

@@ -1,21 +1,34 @@
 {inputs, ...}: {
   perSystem = {
     config,
+    lib,
     pkgs,
     system,
     inputs',
     self',
     ...
   }: let
+    # wasm-bindgen modules to include in the files
+    wasm-modules = {
+      loader = inputs'.wasm-bindgen-service-worker.packages.loader;
+      ui = self'.packages.ui;
+      wasm = self'.packages.wasm;
+    };
+
+    # generate bash script that copies the contents of all the wasm-modules into their respective directories
+    wasm-modules-includes = lib.concatMapStringsSep "\n" (name: ''
+      mkdir -p $out/public/wasm/${name}
+      cp -r ${wasm-modules.${name}}/* $out/public/wasm/${name}
+    '') (builtins.attrNames wasm-modules);
+
     static-files = pkgs.runCommand "static-files" {} ''
       mkdir -p $out
 
       mkdir -p $out/public/wasm
 
       cp -r ${../public}/* $out/public
 
-      cp -r ${self'.packages.wasm}/* $out/public/wasm
-      cp -r ${self'.packages.ui}/* $out/public/wasm
+      ${wasm-modules-includes}
     '';
   in rec {
     packages = {