CommentController.activeCommentThread not updated when navigating from editor gutter (microsoft#223840)

Fixes microsoft#223824

Author: alexr00

src/vs/workbench/contrib/comments/browser/commentThreadZoneWidget.ts

@@ -319,8 +319,11 @@ export class ReviewZoneWidget extends ZoneWidget implements ICommentThreadWidget
 		this._commentThread.collapsibleState = languages.CommentThreadCollapsibleState.Collapsed;
 	}
 
-	public expand() {
+	public expand(setActive?: boolean) {
 		this._commentThread.collapsibleState = languages.CommentThreadCollapsibleState.Expanded;
+		if (setActive) {
+			this.commentService.setActiveCommentAndThread(this.uniqueOwner, { thread: this._commentThread });
+		}
 	}
 
 	public getGlyphPosition(): number {

src/vs/workbench/contrib/comments/browser/commentsController.ts

@@ -1098,7 +1098,7 @@ export class CommentController implements IEditorContribution {
 			const existingCommentsAtLine = this._commentWidgets.filter(widget => widget.getGlyphPosition() === (commentRange ? commentRange.endLineNumber : 0));
 			if (existingCommentsAtLine.length) {
 				const allExpanded = existingCommentsAtLine.every(widget => widget.expanded);
-				existingCommentsAtLine.forEach(allExpanded ? widget => widget.collapse() : widget => widget.expand());
+				existingCommentsAtLine.forEach(allExpanded ? widget => widget.collapse() : widget => widget.expand(true));
 				this.processNextThreadToAdd();
 				return;
 			} else {