Implements first iteration of multi diff editors.

Co-authored-by: Ladislau Szomoru <3372902+lszomoru@users.noreply.github.com>

extensions/git/src/repository.ts

@@ -1658,6 +1658,10 @@ export class Repository implements Disposable {
 		return await this.repository.getCommit(ref);
 	}
 
+	async getCommitFiles(ref: string): Promise<string[]> {
+		return await this.repository.getCommitFiles(ref);
+	}
+
 	async getCommitCount(range: string): Promise<{ ahead: number; behind: number }> {
 		return await this.run(Operation.RevList, () => this.repository.getCommitCount(range));
 	}