Add delete hotspot button to editor

Signed-off-by: Justin Georgi <justin.georgi@gmail.com>

modules/glmv.css

@@ -2,6 +2,10 @@
     cursor: crosshair !important;
 }
 
+.DeletingHotspot {
+    cursor: not-allowed !important;
+}
+
 .Hotspot{
     background: #00000080;
     border-radius: 100%;
@@ -143,6 +147,10 @@
     transform: scaleX(-1);
 }
 
+.preview-button {
+    margin: 2px;
+}
+
 @media (pointer: coarse)  {
     .Hotspot {
         width: 60px;