Added support for acknowledging code of conduct for using public Notebook Gallery (#117)

* minro code edits

* Added support for acknowledging code of conduct

- Added CodeOfConduct component that shows links and a checkbox that must be acknwledged before seeing the public galley
- Added verbose message for notebook publish error (when another notebook with the same name exists in the gallery)
- Added a feature flag for enabling code of conduct acknowledgement

* Added Info Component

* minor edit

* fixed failign tests

* publish tab displayed only when code of conduct accepted

* added code of conduct fetch during publish

* fixed bug

* added test and addressed PR comments

* changed line endings

* added comment

* addressed PR comments

src/Explorer/Controls/NotebookGallery/InfoComponent/InfoComponent.less

@@ -0,0 +1,26 @@
+@import "../../../../../less/Common/Constants.less";
+.infoPanel, .infoPanelMain {
+    display: flex;
+    align-items: center;
+}
+
+.infoPanel {
+    padding-left: 5px;
+    padding-right: 5px;
+}
+
+.infoLabel, .infoLabelMain {
+    padding-left: 5px  
+}
+
+.infoLabel {
+    font-weight: 400
+}
+
+.infoIconMain {
+    color: @AccentMedium
+}
+
+.infoIconMain:hover {
+    color: @BaseMedium
+}