Avoid looking up settings during timeline rendering (#8313)

* Avoid showHiddenEventsInTimeline lookups

* Avoid MSC3531 feature lookups

* Test that showHiddenEventsInTimeline doesn't get looked up while
rendering

* Fix code review nits

Co-authored-by: Travis Ralston <travisr@matrix.org>

src/utils/exportUtils/HtmlExport.tsx

@@ -407,7 +407,7 @@ export default class HTMLExporter extends Exporter {
                 total: events.length,
             }), false, true);
             if (this.cancelled) return this.cleanUp();
-            if (!haveRendererForEvent(event)) continue;
+            if (!haveRendererForEvent(event, false)) continue;
 
             content += this.needsDateSeparator(event, prevEvent) ? this.getDateSeparator(event) : "";
             const shouldBeJoined = !this.needsDateSeparator(event, prevEvent) &&

src/utils/exportUtils/JSONExport.ts

@@ -85,7 +85,7 @@ export default class JSONExporter extends Exporter {
                 total: events.length,
             }), false, true);
             if (this.cancelled) return this.cleanUp();
-            if (!haveRendererForEvent(event)) continue;
+            if (!haveRendererForEvent(event, false)) continue;
             this.messages.push(await this.getJSONString(event));
         }
         return this.createJSONString();

src/utils/exportUtils/PlainTextExport.ts

@@ -112,7 +112,7 @@ export default class PlainTextExporter extends Exporter {
                 total: events.length,
             }), false, true);
             if (this.cancelled) return this.cleanUp();
-            if (!haveRendererForEvent(event)) continue;
+            if (!haveRendererForEvent(event, false)) continue;
             const textForEvent = await this.plainTextForEvent(event);
             content += textForEvent && `${new Date(event.getTs()).toLocaleString()} - ${textForEvent}\n`;
         }