getPropsForSearchResult: Harden to missing conversation

ts/components/MessageSearchResult.md

@@ -230,3 +230,20 @@
   />
 </util.LeftPaneContext>
 ```
+
+#### Empty
+
+```jsx
+<util.LeftPaneContext theme={util.theme}>
+  <MessageSearchResult
+    from={{}}
+    to={{}}
+    snippet="What's <<left>>going<<right>> on?"
+    id="messageId1"
+    conversationId="conversationId1"
+    sentAt={Date.now() - 24 * 60 * 1000}
+    onClick={result => console.log('onClick', result)}
+    i18n={util.i18n}
+  />
+</util.LeftPaneContext>
+```

ts/components/conversation/ContactName.tsx

@@ -24,7 +24,7 @@ export class ContactName extends React.Component<Props> {
 
     return (
       <span className={prefix} dir="auto">
-        <Emojify text={title} />
+        <Emojify text={title || ''} />
         {shouldShowProfile ? ' ' : null}
         {profileElement}
       </span>