fix: update fullscreen state icon

Author: ArgoZhang

src/BootstrapBlazor/wwwroot/modules/fullscreen.js

@@ -14,7 +14,7 @@ export async function toggle(options) {
 
     if (el !== null) {
         if (isFullscreen()) {
-            await document.exitFullscreen()
+            await exitFullscreen(el);
         }
         else {
             await enterFullscreen(el);
@@ -25,6 +25,16 @@ export async function toggle(options) {
 const enterFullscreen = async el => {
     await el.requestFullscreen();
 
+    updateFullscreenState(el);
+}
+
+const exitFullscreen = async el => {
+    await document.exitFullscreen()
+
+    updateFullscreenState(el);
+}
+
+const updateFullscreenState = el => {
     if (!isFullscreen()) {
         el.classList.remove('bb-fs-open');
         document.documentElement.classList.remove('bb-fs-open');