PSFD-455: Iterate on search results for message bubbles

Though not perfect, this is a bit better than it was before. Specifically, we ensure our matching for `isOwnEvent` correctly identifies the user and that the results don't look *awful*. 

There's still room for improvement, but this should be a measurable improvement itself. Most notably, this doesn't fix a couple obvious bugs due to complexity:
* Message bubbles have the wrong corners for the display format (pre-existing).
* The sender's own messages are missing avatars/names. This is just way too complex to fix.

**Requires matrix-org/matrix-js-sdk#2004

Author: turt2live

res/css/views/rooms/_EventBubbleTile.scss

@@ -22,6 +22,27 @@ limitations under the License.
     --maxWidth: 70%;
 }
 
+.mx_RoomView_searchResultsPanel {
+    .mx_EventTile[data-layout=bubble] {
+        .mx_SenderProfile {
+            // Group layout adds a 64px left margin, which we really don't want on search results
+            margin-left: 0;
+        }
+
+        &[data-self=true] {
+            // The avatars end up overlapping, so just hide them
+            .mx_EventTile_avatar {
+                display: none;
+            }
+        }
+
+        // Mirror rough designs for "greyed out" text
+        &.mx_EventTile_contextual {
+            opacity: 0.7;
+        }
+    }
+}
+
 .mx_EventTile[data-layout=bubble] {
     position: relative;
     margin-top: var(--gutterSize);

src/components/views/rooms/EventTile.tsx

@@ -1320,7 +1320,9 @@ export default class EventTile extends React.Component<IProps, IState> {
                             isQuoteExpanded={isQuoteExpanded}
                             setQuoteExpanded={this.setQuoteExpanded}
                         />) : null;
-                const isOwnEvent = this.props.mxEvent?.sender?.userId === MatrixClientPeg.get().getUserId();
+
+                // Use `getSender()` because searched events might not have a proper `sender`.
+                const isOwnEvent = this.props.mxEvent?.getSender() === MatrixClientPeg.get().getUserId();
 
                 // tab-index=-1 to allow it to be focusable but do not add tab stop for it, primarily for screen readers
                 return (