Fix inconsistent setting search results with exact match

Always ignore remote results when an exact match is found. Also get rid of cached new extension results on each search
Fix #78455

src/vs/workbench/contrib/preferences/browser/settingsTreeModels.ts

@@ -536,12 +536,18 @@ export class SearchResultModel extends SettingsTreeModel {
 
 	setResult(order: SearchResultIdx, result: ISearchResult | null): void {
 		this.cachedUniqueSearchResults = null;
+		this.newExtensionSearchResults = null;
+
 		this.rawSearchResults = this.rawSearchResults || [];
 		if (!result) {
 			delete this.rawSearchResults[order];
 			return;
 		}
 
+		if (result.exactMatch) {
+			this.rawSearchResults = [];
+		}
+
 		this.rawSearchResults[order] = result;
 		this.updateChildren();
 	}