Website: Update testimonial video thumbnails (#16483)

Closes: #16360

Changes: 
- Updated the play button on the thumbnails for the testimonial videos
on the homepage to be a separate image.
- Removed three unused images (old versions of video thumbnails)

website/assets/styles/pages/homepage.less

@@ -149,13 +149,17 @@
       align-items: center;
       justify-content: center;
       margin-bottom: 0px;
+      img {
+        height: 48px;
+        width: auto;
+      }
     }
     &:hover {
       box-shadow: 0px 4px 16px 0px #E2E4EA;
     }
     &:first-of-type {
       [purpose='testimonial-video'] {
-        background: url('/images/video-testimonial-nick-fohs-160x120@2x.png');
+        background: url('/images/video-testimonial-thumbnail-nick-fohs-160x120@2x.png');
         background-position: center;
         background-size: cover;
       }
@@ -164,7 +168,7 @@
     }
     &:last-of-type {
       [purpose='testimonial-video'] {
-        background: url('/images/video-testimonial-austin-anderson-160x120@2x.png');
+        background: url('/images/video-testimonial-thumbnail-austin-anderson-160x120@2x.png');
         background-position: center;
         background-size: cover;
       }
@@ -1210,6 +1214,10 @@
         width: 100%;
         height: 228px;
         margin-bottom: 24px;
+        img {
+          height: 90px;
+          width: auto;
+        }
       }
     }
     [purpose='vuln-management-image'] {

website/views/pages/homepage.ejs

@@ -66,6 +66,7 @@
       <div purpose="testimonials" class="d-flex flex-lg-row flex-column justify-content-center card-deck">
         <div purpose="testimonial" class="d-flex align-items-center card" @click="clickOpenVideoModal('nick-fohs')">
           <div purpose="testimonial-video" class="card-title">
+            <img alt="Play video" src="/images/icon-play-48x48@2x.png">
           </div>
           <div purpose="testimonial-text">
             <p purpose="testimonial-quote">“Fleet lets us to be as lightweight as possible while surfacing data to other teams and partners.”</p>
@@ -75,6 +76,7 @@
         </div>
         <div purpose="testimonial" class="d-flex align-items-center card" @click="clickOpenVideoModal('austin-anderson')">
           <div purpose="testimonial-video" class="card-title">
+            <img alt="Play video" src="/images/icon-play-48x48@2x.png">
           </div>
           <div purpose="testimonial-text">
             <p purpose="testimonial-quote">“We can build it exactly the way we want it. Which is just not possible on other platforms.”</p>