Add support mCaptcha as captcha provider (#20458)

https://mcaptcha.org/

Co-authored-by: Felipe Leopoldo Sologuren Gutiérrez <fsologureng@users.noreply.github.com>

web_src/js/features/mcaptcha.js

@@ -0,0 +1,16 @@
+export async function initMcaptcha() {
+  const mCaptchaEl = document.querySelector('.m-captcha');
+  if (!mCaptchaEl) return;
+
+  const {default: mCaptcha} = await import(/* webpackChunkName: "mcaptcha-vanilla-glue" */'@mcaptcha/vanilla-glue');
+  mCaptcha.INPUT_NAME = 'm-captcha-response';
+  const siteKey = mCaptchaEl.getAttribute('data-sitekey');
+  const instanceURL = mCaptchaEl.getAttribute('data-instance-url');
+
+  mCaptcha.default({
+    siteKey: {
+      instanceUrl: new URL(instanceURL),
+      key: siteKey,
+    }
+  });
+}