Upgrade web assets (#219)

* Update assets

* Upgrade linting and other improvments

* Correct linting

* Correction and type check improvements

* Correct type check lib

* Fix lint pathing for VSCode

* Remove duplicate babel config

* Remove editorconfig root attribute from web subdir

* Use double quotes around message

* Simplify ESLint config

* Update web assets

* Allow AMD loader in WebPack

* Bump web dependencies

* Only include FA icons in-use

web/js/lib/theme.mjs

@@ -0,0 +1,42 @@
+export default class {
+    /**
+     * @property {boolean} dark Interal state for dark theme activation.
+     * @private
+     */
+    static #dark = false;
+
+    /**
+     * Inialize the theme class.
+     */
+    static init() {
+      // Check LocalStorage for dark theme selection
+      if (localStorage.getItem('darkTheme') === 'true') {
+        // Update page theme
+        this.set(true);
+      }
+    }
+
+    /**
+     * Set page theme and update local storage variable.
+     *
+     * @param {boolean} dark Whether to activate dark theme.
+     */
+    static set(dark = false) {
+      // Swap CSS to selected theme
+      document.getElementById('pagestyle')
+          .setAttribute('href', 'static/css/' + (dark ? 'dark' : 'main') + '.css');
+
+      // Update local storage
+      localStorage.setItem('darkTheme', dark);
+
+      // Update internal state
+      this.#dark = dark;
+    }
+
+    /**
+     * Swap page theme.
+     */
+    static swap() {
+      this.set(!this.#dark);
+    }
+}