UI: settings show/hide update display (#1072)

* UI: settings show/hide update display

This PR replaces the PR #1003

In this PR, the visual for available update is added to the foreground.

There are new settings to generally show/hide the update display, and only administrators receive the update display.

* change to `Bean`

* Update AppUpdateShowService.java

* add update message

* revision service

* change shouldShow

* Update githubVersion.js

* rm folder

* Update AppUpdateService.java

src/main/resources/static/css/home.css

@@ -89,3 +89,38 @@
 .jumbotron {
   padding: 3rem 3rem; /* Reduce vertical padding */
 }
+
+.lookatme {
+  opacity: 1;
+  position: relative;
+  display: inline-block;
+}
+
+.lookatme::after {
+  color: #e33100;
+  text-shadow: 0 0 5px #e33100;
+  /* in the html, the data-lookatme-text attribute must */
+  /* contain the same text as the .lookatme element */
+  content: attr(data-lookatme-text);
+  padding: inherit;
+  position: absolute;
+  inset: 0 0 0 0;
+  z-index: 1;
+  /* 20 steps / 2 seconds = 10fps */
+  -webkit-animation: 2s infinite Pulse steps(20);
+  animation: 2s infinite Pulse steps(20);
+}
+
+@keyframes Pulse {
+  from {
+    opacity: 0;
+  }
+
+  50% {
+    opacity: 1;
+  }
+
+  to {
+    opacity: 0;
+  }
+}