improve typing by removing as html element (#7212)

* refactor(embeds): use generic HTMLIFrameElement instead of 'as HTMLIFrameElement'

* refactor(embeds): improve types for floatingButton logic

* Fix floating button popup not working

---------

Co-authored-by: Hariom Balhara <hariombalhara@gmail.com>

packages/embeds/embed-core/src/ModalBox/ModalBox.ts

@@ -76,7 +76,7 @@ export class ModalBox extends HTMLElement {
 
   connectedCallback() {
     this.assertHasShadowRoot();
-    const closeEl = this.shadowRoot.querySelector(".close") as HTMLElement;
+    const closeEl = this.shadowRoot.querySelector<HTMLElement>(".close");
     document.addEventListener(
       "keydown",
       (e) => {
@@ -92,9 +92,11 @@ export class ModalBox extends HTMLElement {
       this.close();
     });
 
-    closeEl.onclick = () => {
-      this.close();
-    };
+    if (closeEl) {
+      closeEl.onclick = () => {
+        this.close();
+      };
+    }
   }
 
   constructor() {