[web-client] simple theme: refactor jinja_svg_catalog and cleanup icon names

This patch implements the template generation of the template:

  searx/templates/simple/icons.html

by the way the icon set (the icon names) has been normalized:

  film-outline   --> film
  magnet-outline --> magnet
  ..
  warning        --> alert

Some missing (categorie) icons had been added.

Some of the ionicons are not suitable for a dark theme, we fixed the svg
manually in src/svg/ionicons:

- https://github.com/searxng/searxng/pull/4284#issuecomment-2680550342

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

client/simple/theme_icons.js

@@ -0,0 +1,80 @@
+/**
+ * Generate icons.html for the jinja templates of the simple theme.
+ */
+
+import { argv } from "node:process";
+import { dirname, resolve } from "node:path";
+import { jinja_svg_sets } from "./tools/jinja_svg_catalog.js";
+
+const HERE = dirname(argv[1]) + "/";
+const dest = resolve(HERE, "../../searx/templates/simple/icons.html");
+
+/** @type import("./tools/jinja_svg_catalog.js").JinjaMacro[] */
+const searxng_jinja_macros = [
+  { name: "icon",       class: "ion-icon" },
+  { name: "icon_small", class: "ion-icon-small" },
+  { name: "icon_big",   class: "ion-icon-big" },
+];
+
+
+const sxng_icon_opts ={
+  multipass: true,
+  plugins: [
+    { name: "removeTitle" },
+    { name: "removeXMLNS" },
+    { name: "addAttributesToSVGElement",
+      params: {
+        attributes: [
+          {
+            "aria-hidden": "true",
+          }]}}]
+};
+
+
+/** @type import("./tools/jinja_svg_catalog.js").IconSet */
+const simple_icons = [
+  {
+    base: resolve(HERE, "node_modules/ionicons/dist/svg"),
+    set: {
+      "alert": "alert-outline.svg",
+      "appstore": "apps-outline.svg",
+      "book": "book-outline.svg",
+      "close": "close-outline.svg",
+      "ellipsis-vertical": "ellipsis-vertical-outline.svg",
+      "file-tray-full": "file-tray-full-outline.svg",
+      "film": "film-outline.svg",
+      "globe": "globe-outline.svg",
+      "heart": "heart-outline.svg",
+      "image": "image-outline.svg",
+      "layers": "layers-outline.svg",
+      "location": "location-outline.svg",
+      "magnet": "magnet-outline.svg",
+      "musical-notes": "musical-notes-outline.svg",
+      "navigate-down": "chevron-down-outline.svg",
+      "navigate-left": "chevron-back-outline.svg",
+      "navigate-right": "chevron-forward-outline.svg",
+      "navigate-up": "chevron-up-outline.svg",
+      "people": "people-outline.svg",
+      "play": "play-outline.svg",
+      "radio": "radio-outline.svg",
+      "school": "school-outline.svg",
+      "search": "search-outline.svg",
+      "settings": "settings-outline.svg",
+      "tv": "tv-outline.svg",
+    },
+    svgo_opts: sxng_icon_opts,
+  },
+  // some of the ionicons are not suitable for a dark theme, we fixed the svg
+  // manually in src/svg/ionicons
+  // - https://github.com/searxng/searxng/pull/4284#issuecomment-2680550342
+  {
+    base: resolve(HERE, "src/svg/ionicons"),
+    set: {
+      "information-circle": "information-circle-outline.svg",
+      "newspaper": "newspaper-outline.svg",
+    },
+    svgo_opts: sxng_icon_opts,
+  }
+];
+
+jinja_svg_sets(dest, searxng_jinja_macros, simple_icons);