Website: Add announcement banner (#32603)

Changes:
- Added an announcement banner on the homepage, /login, /register, and
/try-fleet that links to the contact page with the message "$0 MDM
migration"

website/views/pages/entrance/login.ejs

@@ -1,4 +1,7 @@
 <div id="login" v-cloak>
+  <div purpose="announcement-banner">
+    <animated-arrow-button arrow-color="white" text-color="white" href="/contact">$0 MDM migration</animated-arrow-button>
+  </div>
   <div purpose="page-container" class="container">
     <div purpose="page-heading">
       <h1>Welcome to Fleet</h1>

website/views/pages/entrance/signup.ejs

@@ -1,4 +1,7 @@
 <div id="signup" v-cloak>
+  <div purpose="announcement-banner">
+    <animated-arrow-button arrow-color="white" text-color="white" href="/contact">$0 MDM migration</animated-arrow-button>
+  </div>
   <div purpose="page-container" class="container">
     <div purpose="page-heading">
       <h1>Welcome to Fleet</h1>

website/views/pages/fleetctl-preview.ejs

@@ -1,4 +1,7 @@
 <div id="fleetctl-preview" v-cloak>
+  <div purpose="announcement-banner">
+    <animated-arrow-button arrow-color="white" text-color="white" href="/contact">$0 MDM migration</animated-arrow-button>
+  </div>
   <div purpose="page-container" class="d-flex flex-column container">
     <div purpose="page-title">
       <h1>Try Fleet</h1>

website/views/pages/homepage.ejs

@@ -1,4 +1,7 @@
 <div id="homepage" v-cloak>
+  <div purpose="announcement-banner">
+    <animated-arrow-button arrow-color="white" text-color="white" href="/contact">$0 MDM migration</animated-arrow-button>
+  </div>
   <%/* Hero container */%>
   <div purpose="hero-container">
     <div purpose="hero-background-image">