[mod] theme/simple: migrate codebase to TypeScript

TypeScript is a superset of JavaScript, converting the entire theme to
TypeScript allows us to receive much more feedback on possible issues made in
package updates or our own typos, furthermore, it allows to transpile properly
to lower specs. This PR couldn't be done in smaller commits, a lot of work
needed to make everything *work properly*:

- A browser baseline has been set that requires minimum **Chromium 93, Firefox
  92 and Safari 15** (proper visuals/operation on older browser versions is not
  guaranteed)
- LightningCSS now handles minification and prefix creation for CSS.
- All hardcoded polyfills and support for previous browser baseline versions
  have been removed.
- Convert codebase to TypeScript.
- Convert IIFE to ESM, handling globals with IIFE is cumbersome, ESM is the
  standard for virtually any use of JS nowadays.
- Vite now builds the theme without the need for `vite-plugin-static-copy`.
- `searxng.ready` now accepts an array of conditions for the callback to be
  executed.
- Replace `leaflet` with `ol` as there were some issues with proper Vite
  bundling.
- Merged `head` with `main` script, as head was too small now.
- Add `assertElement` to properly check the existence of critical DOM elements.
- `searxng.on` renamed to `searxng.listen` with some handling improvements.

1 files changed, 120 insertions, 0 deletions

diff --git a/client/simple/tools/jinja_svg_catalog.ts b/client/simple/tools/jinja_svg_catalog.ts
new file mode 100644
index 000000000..1fa1a6676
--- /dev/null
+++ b/client/simple/tools/jinja_svg_catalog.ts
@@ -0,0 +1,120 @@
+import fs from "node:fs";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+import { Edge } from "edge.js";
+import { type Config as SvgoConfig, optimize as svgo } from "svgo";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const __jinja_class_placeholder__ = "__jinja_class_placeholder__";
+
+// A set of icons
+export type IconSet = {
+  // Object of SVG icons, where property name is the name of the icon and value is the src of the SVG (relative to base)
+  set: Record<string, string>;
+  // Folder in which the SVG src files are located
+  base: string;
+  // svgo options for this set
+  svgo_opts: SvgoConfig;
+};
+
+// Mapping of icon name to SVG source file
+type IconSVG = {
+  // Name of the icon isource file
+  name: string;
+  // Name of the destination file
+  src: string;
+  // Options passed to svgo
+  svgo_opts: SvgoConfig;
+};
+
+// Arguments to create a jinja macro
+export type JinjaMacro = {
+  // Name of the jinja macro
+  name: string;
+  // SVG's class name (value of XML class attribute)
+  class: string;
+};
+
+/**
+ * Generate a jinja template with a catalog of SVG icons that can be
+ * used in other HTML jinja templates.
+ *
+ * @param dest - filename of the generate jinja template.
+ * @param macros - Jinja macros to create.
+ * @param items - Array of SVG items.
+ */
+export const jinja_svg_catalog = (dest: string, macros: JinjaMacro[], items: IconSVG[]) => {
+  const svg_catalog: Record<string, string> = {};
+  const edge_template = resolve(__dirname, "jinja_svg_catalog.html.edge");
+
+  for (const item of items) {
+    // JSON.stringify & JSON.parse are used to create a deep copy of the item.svgo_opts object
+    const svgo_opts: SvgoConfig = JSON.parse(JSON.stringify(item.svgo_opts));
+
+    svgo_opts.plugins?.push({
+      name: "addClassesToSVGElement",
+      params: {
+        classNames: [__jinja_class_placeholder__]
+      }
+    });
+
+    try {
+      const raw = fs.readFileSync(item.src, "utf8");
+      const opt = svgo(raw, svgo_opts);
+
+      svg_catalog[item.name] = opt.data;
+    } catch (err) {
+      console.error(`ERROR: jinja_svg_catalog processing ${item.name} src: ${item.src} -- ${err}`);
+      throw err;
+    }
+  }
+
+  fs.mkdir(dirname(dest), { recursive: true }, (err) => {
+    if (err) throw err;
+  });
+
+  const ctx = {
+    svg_catalog: svg_catalog,
+    macros: macros,
+    edge_template: edge_template,
+    __jinja_class_placeholder__: __jinja_class_placeholder__,
+    // see https://github.com/edge-js/edge/issues/162
+    open_curly_brace: "{{",
+    close_curly_brace: "}}"
+  };
+
+  const jinjatmpl = Edge.create().renderRawSync(fs.readFileSync(edge_template, "utf-8"), ctx);
+
+  fs.writeFileSync(dest, jinjatmpl);
+  console.log(`[jinja_svg_catalog] created: ${dest}`);
+};
+
+/**
+ * Calls jinja_svg_catalog for a collection of icon sets where each set has its
+ * own parameters.
+ *
+ * @param dest - filename of the generate jinja template.
+ * @param macros - Jinja macros to create.
+ * @param sets - Array of SVG sets.
+ */
+export const jinja_svg_sets = (dest: string, macros: JinjaMacro[], sets: IconSet[]) => {
+  const items: IconSVG[] = [];
+  const all: string[] = [];
+
+  for (const obj of sets) {
+    for (const [name, file] of Object.entries(obj.set)) {
+      if (all.includes(name)) {
+        throw new Error(`ERROR: ${name} has already been defined`);
+      }
+
+      all.push(name);
+      items.push({
+        name: name,
+        src: resolve(obj.base, file),
+        svgo_opts: obj.svgo_opts
+      });
+    }
+  }
+
+  jinja_svg_catalog(dest, macros, items);
+};