Hide the tool component if hidden set to true

Change-Id: Ic421e9dbdca0d1fb72f73876d3eef64e3edff0cf

gr-image-diff-tool/gr-image-diff-tool_html.js

diff --git a/gr-image-diff-tool/gr-image-diff-tool_html.js b/gr-image-diff-tool/gr-image-diff-tool_html.js
index 887a028..212298c 100644
--- a/gr-image-diff-tool/gr-image-diff-tool_html.js
+++ b/gr-image-diff-tool/gr-image-diff-tool_html.js
@@ -22,6 +22,12 @@
     display: block;
     font-family: var(--font-family);
   }
+  /** This is needed as we have explicit display on :host
+    * which will override hidden from shared-styles
+    */
+  :host[hidden] {
+    display: none;
+  }
   #header {
     align-items: center;
     border-bottom: 1px solid var(--border-color, #ddd);