[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, 0 insertions, 44 deletions

diff --git a/client/simple/tools/plg.js b/client/simple/tools/plg.js
deleted file mode 100644
index 74e488fc4..000000000
--- a/client/simple/tools/plg.js
+++ /dev/null
@@ -1,44 +0,0 @@
-/**
- * Custom vite plugins to build the web-client components of the simple theme.
- *
- * HINT:
- *
- *   This is an inital implementation for the migration of the build process
- *   from grunt to vite.  For fully support (vite: build & serve) more work is
- *   needed.
- */
-
-import { svg2png, svg2svg } from "./img.js";
-
-/**
- * Vite plugin to convert a list of SVG files to PNG.
- *
- * @param {import('./img.js').Src2Dest[]} items - Array of SVG files (src: SVG, dest:PNG) to convert.
- */
-function plg_svg2png(items) {
-  return {
-    name: "searxng-simple-svg2png",
-    apply: "build", // or 'serve'
-    async writeBundle() {
-      await svg2png(items);
-    }
-  };
-}
-
-/**
- * Vite plugin to optimize SVG images for WEB.
- *
- * @param {import('./img.js').Src2Dest[]} items - Array of SVG files (src:SVG, dest:SVG) to optimize.
- * @param {import('svgo').Config} svgo_opts - Options passed to svgo.
- */
-function plg_svg2svg(items, svgo_opts) {
-  return {
-    name: "searxng-simple-svg2png",
-    apply: "build", // or 'serve'
-    async writeBundle() {
-      await svg2svg(items, svgo_opts);
-    }
-  };
-}
-
-export { plg_svg2png, plg_svg2svg };